#include<bits/stdc++.h>
using namespace std;
using lli = unsigned long long;
const lli maxN = 2e5 + 5;
const lli maxA = 1e11;
const lli base = 1000000000003;
lli a[maxN],n,c,k,q,d[maxN],g[maxN],g1[maxN],f[maxN],f1[maxN];
lli st[2 * maxN],st1[2 * maxN];
void build()
{
    for (int i = n;i <= (2 * n - 2);++i)
    {
        st[i] = d[i - n + 1] * g[i - n];
        st1[i] = d[i - n + 1] * f[i - n];
    }
    for (int i = n - 1;i > 0;--i)
    {
        st[i] = (st[i << 1 | 1] + st[i << 1]);
        st1[i] = (st1[i << 1 | 1] + st1[i << 1]);
    }
}
void update(int i,lli val)
{
    if (i == 0 || i == n) return;
    i += (n - 1);
    st[i] = ((st[i] + val * g[i - n]));
    st1[i] = ((st1[i] + val * f[i - n]));
    for (;i > 0;i >>= 1)
    {
        st[i >> 1] = ((st[i ^ 1] + st[i]));
        st1[i >> 1] = ((st1[i ^ 1] + st1[i]));
    }
}
lli get(int l,int r)
{
    lli res = 0;
    ++r;
    for (l += (n - 1),r += (n - 1);l < r;l >>= 1,r >>= 1)
    {
        if (l & 1) res = (res + st[l++]);
        if (r & 1) res = (res + st[--r]);
    }
    return res;
}
lli get1(int l,int r)
{
    lli res = 0;
    ++r;
    for (l += (n - 1),r += (n - 1);l < r;l >>= 1,r >>= 1)
    {
        if (l & 1) res = (res + st1[l++]);
        if (r & 1) res = (res + st1[--r]);
    }
    return res;
}
void input()
{
    cin >> n >> q >> k >> c;
    for (int i = 1;i <= n;++i)
    {
        cin >> a[i];
    }
    for (int i = 1;i < n;++i) d[i] = a[i + 1] - a[i] + maxA;
    g[0] = 1;f[0] = 1;
    g1[0] = g[0] * (k + 2 * maxA);
    f1[0] = f[0] * (k + 2 * maxA);
    for (int i = 1;i <= n;++i)
    {
        g[i] = (g[i - 1] * base);
        g1[i] = (g1[i - 1] + g[i] * (k + 2 * maxA));
        f[i] = (f[i - 1] * base);
        f1[i] = (f1[i - 1] + f[i] * (k + 2 * maxA));
    }
    //cout << (g1[3] - g1[2]) << "\n";
    build();
}
bool check(int r,int i)
{
    lli h1 = get(i + 1,i + r - 1);
    lli h2 = get(i - r,i - 2) * g[r + 1];
    lli h3 = get1(i + 1,i + r - 1);
    lli h4 = get1(i - r,i - 2) * f[r + 1];
    return (((h1 + h2) == ((g1[i + r - 2] - g1[i - 1]))) && ((h3 + h4) == ((f1[i + r - 2] - f1[i - 1]))));
}
void solve()
{
    for (int i = 1;i <= q;++i)
    {
        lli t,x,y,v;
        cin >> t;
        if (t == 2)
        {
            cin >> x;
            if (d[x] + d[x - 1] != k + c + 2 * maxA) {cout << 0 << "\n";continue;}
            int dist = min(x - 1,n - x);
            int l = 2,r = dist,res = 1;
            while (l <= r)
            {
                int mid = (l + r) / 2;
                if (check(mid,x))
                {
                    res = mid;
                    l = mid + 1;
                }
                else r = mid - 1;
            }
            cout << res << "\n";
        }
        else
        {
            cin >> x >> y >> v;
            update(x - 1,v);
            update(y,-v);
            d[x - 1] += v;
            d[y] -= v;
            //cout << (((get(4,4) * (modulo(g[3],Mod)))) + ((get(1,1) * (modulo(g[0],Mod))))) << " " << g1[0] << "A ";
            //cout << "\n";
        }
    }
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
//    freopen("C1.inp","r",stdin);
//    freopen("C1.out","w",stdout);
    input();
    solve();
}