#include <bits/stdc++.h>
using namespace std;
using ll=long long;
#define int long long
template <class S, S (*op)(S, S), S (*e)()>
struct Segtree {
int _n, size, log;
vector<S> d;
void update(int k) {
d[k] = op(d[2 * k], d[2 * k + 1]);
}
Segtree() : Segtree(0) {
}
Segtree(int n) : Segtree(vector<S>(n, e())) {
}
Segtree(const vector<S>& v) : _n(int(v.size())) {
size = bit_ceil((unsigned)_n);
log = countr_zero((unsigned)size);
d = vector<S>(2 * size, e());
for (int i = 0; i < _n; i++) d[size + i] = v[i];
for (int i = size - 1; i >= 1; i--) {
update(i);
}
}
void set(int p, S x) {
p += size;
d[p] = x;
for (int i = 1; i <= log; i++) update(p >> i);
}
S get(int p) {
return d[p + size];
}
S prod(int l, int r) {
S sml = e(), smr = e();
l += size;
r += size;
while (l < r) {
if (l & 1) sml = op(sml, d[l++]);
if (r & 1) smr = op(d[--r], smr);
l >>= 1;
r >>= 1;
}
return op(sml, smr);
}
S all_prod() {
return d[1];
}
template <bool (*f)(S)>
int max_right(int l) {
return max_right(l, [](S x) { return f(x); });
}
template <class F>
int max_right(int l, F f) {
if (l == _n) return _n;
l += size;
S sm = e();
do {
while (l % 2 == 0) l >>= 1;
if (!f(op(sm, d[l]))) {
while (l < size) {
l = (2 * l);
if (f(op(sm, d[l]))) {
sm = op(sm, d[l]);
l++;
}
}
return l - size;
}
sm = op(sm, d[l]);
l++;
} while ((l & -l) != l);
return _n;
}
template <bool (*f)(S)>
int min_left(int r) {
return min_left(r, [](S x) { return f(x); });
}
template <class F>
int min_left(int r, F f) {
if (r == 0) return 0;
r += size;
S sm = e();
do {
r--;
while (r > 1 && (r % 2)) r >>= 1;
if (!f(op(d[r], sm))) {
while (r < size) {
r = (2 * r + 1);
if (f(op(d[r], sm))) {
sm = op(d[r], sm);
r--;
}
}
return r + 1 - size;
}
sm = op(d[r], sm);
} while ((r & -r) != r);
return 0;
}
};
ll op(ll a,ll b){
return a+b;
}
ll e(){
return 0ll;
}
signed main() {
int N,K,M,Q;
cin>>N>>K>>M>>Q;
int M0,M1,M2;
M0=K-1;
M1=M+1;
M2=N-K+1;
vector<ll> X0(M0);
vector<ll> X2(M2);
for(int i=0;i<N;i++){
if (i<M0){
cin>>X0[i];
}
else{
cin>>X2[M2-1-(i-M0)];
}
}
vector<ll> X1(M1);
for(int m=0;m<M1;m++){
cin>>X1[m];
}
const ll inf=1ll<<60;
Segtree<ll,op,e> ST0(X0);
Segtree<ll,op,e> ST1(X1);
Segtree<ll,op,e> ST2(X2);
for(int q=0;q<Q;q++){
char s;
cin>>s;
if(s=='q'){
int x,y;cin>>x>>y;
x-=1;y-=1;
ll ans=inf;
function<ll(ll,ll)> dist=[&](ll x,ll y){
ll ans=inf;
if(0<=x&&x<=K-1&&0<=y&&y<=K-1){
int l=x;
int r=y;
if(l>r){
swap(l,r);
}
ans=min(ans,ST0.prod(l,r));
}
if((K-1<=x&&x<=N-1||x==0)&&(K-1<=y&&y<=N-1||y==0)){
int l=(x==0?0:N-x),r=(y==0?0:N-y);
if(l>r){
swap(l,r);
}
ans=min(ans,ST2.prod(l,r));
}
if((N<=x&&x<=N+M-1||x==0||x==K-1)&&(N<=y&&y<=N+M-1||y==0||y==K-1)){
int l;
if(x==0){
l=0;
}
else if(x==K-1){
l=M1;
}
else{
l=x-(N-1);
}
int r;
if(y==0){
r=0;
}
else if(y==K-1){
r=M1;
}
else{
r=y-(N-1);
}
if(l>r){
swap(l,r);
}
ans=min(ans,ST1.prod(l,r));
}
return ans;
};
ans=min(ans,dist(x,y));
ans=min(ans,dist(x,0)+dist(0,y));
ans=min(ans,dist(x,K-1)+dist(K-1,y));
ans=min(ans,dist(x,0)+dist(0,K-1)+dist(K-1,y));
ans=min(ans,dist(x,K-1)+dist(K-1,0)+dist(0,y));
if(ans>=inf){
cout<<"impossible"<<"\n";
}
else{
cout<<ans<<"\n";
}
}
else if(s=='c'){
int i;cin>>i;
i-=1;
if(i<K-1){
ST0.set(i,inf+X0[i]-ST0.get(i));
}
else{
ST2.set(N-1-i,inf+X2[i]-ST2.get(i));
}
}
else{
int i;cin>>i;
ST1.set(i,inf+X1[i]-ST1.get(i));
}
}
}