#include<bits/stdc++.h>
using namespace std;
using lli = long long;
const lli maxN = 2e5 + 5;
const lli maxA = 5e6;
const lli base = 1e9 + 3;
const lli Mod = 1e9 + 7;
const lli Mod1 = 1000000111;
lli a[maxN],n,c,k,q,d[maxN],g[maxN],g1[maxN],f[maxN],f1[maxN];
lli st[4 * maxN],st1[4 * maxN];
lli modulo(lli a,lli b)
{
    lli m = a,n = b,xm = 1,xn = 0,xr,r,q;
    while (n != 0)
    {
        q = m / n;
        r = m - q * n;
        xr = xm - q * xn;
        xm = xn;xn = xr;
        m = n;n = r;
    }
    return xm;
}
void build(int id,int l,int r)
{
    if (l == r)
    {
        st[id] = g[l - 1] * d[l] % Mod;
        st1[id] = f[l - 1] * d[l] % Mod1;
        return;
    }
    int mid = (l + r) / 2;
    build(id * 2,l,mid);
    build(id * 2 + 1,mid + 1,r);
    st[id] = (st[id * 2] + st[id * 2 + 1]) % Mod;
    st1[id] = (st1[id * 2] + st1[id * 2 + 1]) % Mod1;
}
void update(int id,int l,int r,int x,lli val)
{
    if (x > r || x < l) return;
    if (l == r)
    {
        st[id] = (st[id] + (val * g[l - 1] % Mod + Mod)) % Mod;
        st1[id] = (st1[id] + (val * f[l - 1] % Mod1 + Mod1)) % Mod1;
        return;
    }
    int mid = (l + r) / 2;
    update(id * 2,l,mid,x,val);
    update(id * 2 + 1,mid + 1,r,x,val);
    st[id] = (st[id * 2] + st[id * 2 + 1]) % Mod;
    st1[id] = (st1[id * 2] + st1[id * 2 + 1]) % Mod1;
}
lli get(int id,int l,int r,int u,int v)
{
    if (l > v || r < u) return 0;
    if (u <= l && r <= v) return st[id];
    int mid = (l + r) / 2;
    return (get(id * 2,l,mid,u,v) + get(id * 2 + 1,mid + 1,r,u,v)) % Mod;
}
lli get1(int id,int l,int r,int u,int v)
{
    if (l > v || r < u) return 0;
    if (u <= l && r <= v) return st1[id];
    int mid = (l + r) / 2;
    return (get1(id * 2,l,mid,u,v) + get1(id * 2 + 1,mid + 1,r,u,v)) % Mod1;
}
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) % Mod;
    f1[0] = f[0] * (k + 2 * maxA) % Mod1;
    for (int i = 1;i <= n;++i)
    {
        g[i] = (g[i - 1] * base) % Mod;
        g1[i] = (g1[i - 1] + g[i] * (k + 2 * maxA % Mod) % Mod) % Mod;
        f[i] = (f[i - 1] * base) % Mod1;
        f1[i] = (f1[i - 1] + f[i] * (k + 2 * maxA % Mod1) % Mod1) % Mod1;
    }
    build(1,1,n - 1);
}
bool check(int r,int i)
{
    lli h1 = get(1,1,n - 1,i + 1,i + r - 1) * ((modulo(g[i],Mod) % Mod + Mod) % Mod) % Mod;
    lli h2 = get(1,1,n - 1,i - r,i - 2) * ((modulo(g[i - r - 1],Mod) % Mod + Mod) % Mod) % Mod;
    lli h3 = get1(1,1,n - 1,i + 1,i + r - 1) * ((modulo(f[i],Mod1) % Mod1 + Mod1) % Mod1) % Mod1;
    lli h4 = get1(1,1,n - 1,i - r,i - 2) * ((modulo(f[i - r - 1],Mod1) % Mod1 + Mod1) % Mod1) % Mod1;
    //cout << (h1 + h2) % Mod << " " << g1[r - 2] << " " << r << " AAA\n";
    return (((h1 + h2) % Mod == g1[r - 2]) && ((h4 + h3) % Mod == f1[r - 2]));
}
void solve()
{
    //for (int j = 1;j <= n - 1;++j) cout << (((get(1,1,n - 1,j,j) * (modulo(g[j - 1],Mod) + Mod)) % Mod - maxA) % Mod + Mod) % Mod << "\n";
    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(1,1,n - 1,x - 1,v);
            update(1,1,n - 1,y,-v);
            d[x - 1] += v;
            d[y] -= v;
            //cout << (((get(4,4) * (modulo(g[3],Mod) + Mod)) % Mod) % Mod + ((get(1,1) * (modulo(g[0],Mod) + Mod)) % Mod) % Mod) % 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();
}