#include <bits/stdc++.h>
using namespace std;
#define ll long long
#ifdef LOCAL
template<class t,class u>ostream& operator<<(ostream& os,const pair<t,u>& p){return os<<"("<<p.first<<","<<p.second<<")";}
#endif
template<class t>ostream& operator<<(ostream& os,const vector<t>& v){if(v.size())os<<v[0];for(int i=1; i<v.size(); i++)os<<' '<<v[i]; return os;}
const int inf = 0x3f3f3f3f;
const ll INF = inf;
int n, m, t, k, a, b, c, d, cnt, mark, an, oT_To, x, y, z, q;
ll ans;

int check(int x) {
    int res = 0;
    if (x == 1 || x == k) res |= 7;
    if (x < k) res |= 1;
    if (x > k && x <= n) res |= 2;
    if (x > n) res |= 3;
}

template<typename T>
struct Fenwick {
    int n;
    std::vector<T> a;

    Fenwick(int n = 0) {
        init(n);
    }

    void init(int n) {
        this->n = n;
        a.assign(n, T());
    }

    void add(int x, T v) {
        for (int i = x + 1; i <= n; i += i & -i) {
            a[i - 1] += v;
        }
    }

    T sum(int x) {
        auto ans = T();
        for (int i = x; i > 0; i -= i & -i) {
            ans += a[i - 1];
        }
        return ans;
    }

    T rangeSum(int l, int r) {
        return sum(r) - sum(l);
    }
};
struct Solver {
	void solve() {
        cin >> n >> k >> m >> q;
        vector <ll> vc (n+1), vx(m+1);
        vector vf(3, Fenwick<ll>(n+m+2) );
        auto VC(vc), VX(vx);
        for (int i = 1; i < k; ++i) {
            cin >> VC[i];
            vf[0].add(i+1, VC[i]);
        }
        for (int i = k; i <= n; ++i) {
            cin >> VC[i];
            vf[1].add(i+1, VC[i]);
        }

        for (int i = 0; i <= m; ++i) {
            cin >> VX[i];
            vf[2].add(i+2, VX[i]);
        }

        auto get1 = [&](int x){
            ll res = INF;
            if (x > n) {
                x -= n;
                return vf[2].rangeSum(1, x+1);
            } else {
                if (x >= k) {
                    res = min(res, vf[1].rangeSum(x+1, n+2));
                }
                if (x <= k) {
                    res = min(res, vf[0].rangeSum(1, x+1));
                }
            }
            return res;
        };

        auto getk = [&](int x) {
            ll res = INF;
            if (x > n) {
                x -= n;
                return vf[2].rangeSum(x+1, m+2);
            } else {
                if (x >= k) {
                    res = min(res, vf[1].rangeSum(k+1, x+1));
                } else {
                    res = min(res, vf[0].rangeSum(x+1, k+1));
                }
            }
            return res;
        };
//        cout << "vf[0].rangeSum(2, 4): " << vf[0].rangeSum(4, 5) << '\n';
        char ch;
        while (q--) {
            cin >> ch;
            if (ch == 'x') {
                cin >> a;
                if (vx[a]) {
                    vf[2].add(a+2, -INF);
                } else {
                    vf[2].add(a+2, INF);
                }
                vx[a] = !vx[a];
            } else if (ch == 'c') {
                cin >> a;
                if (vc[a]) {
                    if (a < k) {
                        vf[0].add(a+1, -INF);
                    } else {
                        vf[1].add(a+1, -INF);
                    }
                } else {
                    if (a < k) {
                        vf[0].add(a+1, INF);
                    } else {
                        vf[1].add(a+1, INF);
                    }
                }
                vc[a] = !vc[a];
            } else if (ch == 'q') {
                cin >> a >> b;
                if (a > b) swap(a, b);
                ll a1 = get1(a), ak = getk(a);
                ll b1 = get1(b), bk = getk(b);
                ll k1 = vf[2].sum(m+3);
                ans = min({INF, a1+b1, ak+bk, a1+k1+bk, ak+k1+b1});
                if (a > n && b > n) {
                    ans = min(ans, abs(a1-b1));
                } else {
                    if (a >= k && b >= k) {
                        ans = min(ans, vf[1].rangeSum(a+1, b+1));
                    }
                    if (a <= k && b <= k) {
                        ans = min(ans, vf[0].rangeSum(a+1, b+1));
                    }
                }
                if (ans >= INF) {
                    cout << "impossible\n";
                } else cout << ans << '\n';
            }
        }

//
//        v1[0][1] = v1[1][1] = v1[2][1] = 0;
//        vk[0][k] = vk[1][k] = vk[2][k] = 0;
//        // 0 -> 1-k
//        for (int i = 2; i <= k; ++i) {
//            v1[0][i] = v1[0][i-1] + vc[i-1];
//        }
//        for (int i = k-1; i >= 1; --i) {
//            vk[0][i] = vk[0][i+1] + vc[i];
//        }
//
//        // 1 -> k-n
//        for (int i = k+1; i <= n; ++i) {
//            vk[1][i] = vk[1][i-1] + vc[i-1];
//        }
//        v1[1][n+1] = 0;
//        for (int i = n; i >= k; --i) {
//            v1[1][i] = v1[1][i+1] + vc[i];
//        }
//        vk[1][1] = v1[1][k];
//        v1[1][n+1] = INF;
//
//
//
//        // 2 -> 1-n+1-n+m-k
//        v1[2][n+1] = vx[0];
//        for (int i = n+2; i <= n+m; ++i) {
//            v1[2][i] = v1[2][i-1] + vx[i-n-1];
//        }
//        vk[2][1] = v1[2][k] = v1[2][n+m] + vx[m];
//        vk[2][n+m+1] = 0;
//        for (int i = n+m; i >= n+1; --i) {
//            vk[2][i] = vk[2][i+1] + vx[i - n];
//        }
//        vk[2][n+m+1] = INF;
//
//
//
//        while (vp.size()) {
//            auto [x, y] = vp.back(); vp.pop_back();
//            if (y > 0) {
//                ans = INF;
//                int fx = check(x), fy = check(y);
//                ll xto1 = min({v1[0][x], v1[1][x], v1[2][x]});
//                ll xtok = min({vk[0][x], vk[1][x], vk[2][x]});
//                ll yto1 = min({v1[0][y], v1[1][y], v1[2][y]});
//                ll ytok = min({vk[0][y], vk[1][y], vk[2][y]});
//                ans = min({ans, xto1 + yto1, xtok + ytok, xto1 + v1[2][k] + ytok, xtok + v1[2][k] + yto1});
//                for (int i : {0, 1, 2}) {
//                    int j = i<<1;
//                    if ((fx&j) && (fy&j)) {
//                        ans = min(ans, abs(v1[i][x] - v1[])
//                    }
//                }
//
//            }
//            else {
//                y = -y;
//                if (x == 0) {
//                    vx[y] = VX[y];
//                    // do it
//                    assert(0);
//                } else {
//                    vc[y] = VX[y];
//                    // do it
//                    assert(0);
//
//                }
//            }
//        }


	}
};

int main () {
    ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
//    cout << "INF: " << INF << '\n';
    oT_To = 1;
//    cin >> oT_To;
    while (oT_To--) {
    	Solver solver;
        solver.solve();
    }
}

answer.code: In function ‘int check(int)’:
answer.code:19:1: warning: no return statement in function returning non-void [-Wreturn-type]
   19 | }
      | ^
answer.code: In member function ‘void Solver::solve()’:
answer.code:57:16: error: missing template arguments before ‘vf’
   57 |         vector vf(3, Fenwick<ll>(n+m+2) );
      |                ^~
answer.code:61:13: error: ‘vf’ was not declared in this scope; did you mean ‘vx’?
   61 |             vf[0].add(i+1, VC[i]);
      |             ^~
      |             vx
answer.code:65:13: error: ‘vf’ was not declared in this scope; did you mean ‘vx’?
   65 |             vf[1].add(i+1, VC[i]);
      |             ^~
      |             vx
answer.code:70:13: error: ‘vf’ was not declared in this scope; did you mean ‘vx’?
   70 |             vf[2].add(i+2, VX[i]);
      |             ^~
      |             vx
answer.code: In lambda function:
answer.code:77:24: error: ‘vf’ was not declared in this scope; did you mean ‘vx’?
   77 |                 return vf[2].rangeSum(1, x+1);
      |                        ^~
      |                        vx
answer.code:80:36: error: ‘vf’ was not declared in this scope; did you mean ‘vx’?
   80 |                     res = min(res, vf[1].rangeSum(x+1, n+2));
      |                                    ^~
      |                                    vx
answer.code:83:36: error: ‘vf’ was not declared in this scope; did you mean ‘vx’?
   83 |                     res = min(res, vf[0].rangeSum(1, x+1));
      |                                    ^~
      |                                    vx
answer.code: In lambda function:
answer.code:93:24: error: ‘vf’ was not declared in this scope; did you mean ‘vx’?
   93 |                 return vf[2].rangeSum(x+1, m+2);
      |                        ^~
      |                        vx
answer.code:96:36: error: ‘vf’ was not declared in this scope; did you mean ‘vx’?
   96 |                     res = min(res, vf[1].rangeSum(k+1, x+1));
      |                                    ^~
      |                                    vx
answer.code:98:36: error: ‘vf’ was not declared in this scope; did you mean ‘vx’?
   98 |                     res = min(res, vf[0].rangeSum(x+1, k+1));
      |                                    ^~
      |                                    vx
answer.code: In member function ‘void Solver::solve()’:
answer.code:110:21: error: ‘vf’ was not declared in this scope; did you mean ‘vx’?
  110 |                     vf[2].add(a+2, -INF);
      |                     ^~
      |                     vx
answer.code:112:21: error: ‘vf’ was not declared in this scope; did you mean ‘vx’?
  112 |                     vf[2].add(a+2, INF);
      |                     ^~
      |                     vx
answer.code:119:25: error: ‘vf’ was not declared in this scope; did you mean ‘vx’?
  119 |                         vf[0].add(a+1, -INF);
      |                         ^~
      |                         vx
answer.code:121:25: error: ‘vf’ was not declared in this scope; did you mean ‘vx’?
  121 |                         vf[1].add(a+1, -INF);
      |                         ^~
      |                         vx
answer.code:125:25: error: ‘vf’ was not declared in this scope; did you mean ‘vx’?
  125 |                         vf[0].add(a+1, INF);
      |                         ^~
      |                         vx
answer.code:127:25: error: ‘vf’ was not declared in this scope; did you mean ‘vx’?
  127 |                         vf[1].add(a+1, INF);
      |                         ^~
      |                         vx
answer.code:136:25: error: ‘vf’ was not declared in this scope; did you mean ‘vx’?
  136 |                 ll k1 = vf[2].sum(m+3);
      |                         ^~
      |                         vx