#include<bits/stdc++.h>
using namespace std;
#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops")
#define ALL(v) v.begin(),v.end()
#define For(i,_) for(int i=0,i##end=_;i<i##end;++i) // [0,_)
#define FOR(i,_,__) for(int i=_,i##end=__;i<i##end;++i) // [_,__)
#define Rep(i,_) for(int i=(_)-1;i>=0;--i) // [0,_)
#define REP(i,_,__) for(int i=(__)-1,i##end=_;i>=i##end;--i) // [_,__)
typedef long long ll;
typedef unsigned long long ull;
#define V vector
#define pb push_back
#define pf push_front
#define qb pop_back
#define qf pop_front
#define eb emplace_back
typedef pair<int,int> pii;
typedef pair<ll,int> pli;
#define fi first
#define se second
const int dir[4][2]={{-1,0},{0,1},{1,0},{0,-1}},inf=0x3f3f3f3f,mod=1e9+7;
const ll infl=0x3f3f3f3f3f3f3f3fll;
template<class T>inline bool ckmin(T &x,const T &y){return x>y?x=y,1:0;}
template<class T>inline bool ckmax(T &x,const T &y){return x<y?x=y,1:0;}
int init=[](){return cin.tie(nullptr)->sync_with_stdio(false),0;}();
int main(){
    int t_case=1;
    //scanf("%d",&t_case);
    while(t_case--){
        int b,k,n,q;
        scanf("%d%d%d%d",&n,&q,&k,&b);
        V<ull>bs(n+1),pre(n+1);
        bs[0]=pre[0]=1;
        For(i,n)pre[i+1]=pre[i]+(bs[i+1]=bs[i]*23333);
        V<int>a(n);
        For(i,n){
            scanf("%d",&a[i]);
            (a[i]*=2)-=i*k;
        }
        V<ull>h(n<<2),h2(n<<2);
        auto build=[&](auto &&self,int p,int l,int r){
            if(l==r){
                h[p]=h2[p]=a[l];
                return;
            }
            int mid=l+r>>1;
            self(self,p<<1,l,mid),self(self,p<<1|1,mid+1,r);
            h[p]=h[p<<1]*bs[r-mid]+h[p<<1|1],h2[p]=h2[p<<1]+h2[p<<1|1]*bs[mid-l+1];
        };
        build(build,1,0,n-1);
        V<int>tag(n<<2);
        auto modify=[&](auto &&self,int p,int l,int r,int ql,int qr,int v){
            if(ql<=l&&r<=qr){
                ull add=pre[r-l]*v;
                h[p]+=add,h2[p]+=add,tag[p]+=v;
                return;
            }
            int mid=l+r>>1;
            if(tag[p]){
                ull add=pre[mid-l]*tag[p];
                h[p<<1]+=add,h2[p<<1]+=add,tag[p<<1]+=tag[p];
                add=pre[r-mid-1]*tag[p];
                h[p<<1|1]+=add,h2[p<<1|1]+=add,tag[p<<1|1]+=tag[p];
                tag[p]=0;
                return;
            }
            if(ql<=mid)self(self,p<<1,l,mid,ql,qr,v);
            if(qr>mid)self(self,p<<1|1,mid+1,r,ql,qr,v);
            h[p]=h[p<<1]*bs[r-mid]+h[p<<1|1],h2[p]=h2[p<<1]+h2[p<<1|1]*bs[mid-l+1];
        };
        ull ans;
        auto query=[&](auto &&self,int p,int l,int r,int ql,int qr){
            if(ql<=l&&r<=qr){
                ans=ans*bs[r-l+1]+h[p];
                return;
            }
            int mid=l+r>>1;
            if(tag[p]){
                ull add=pre[mid-l]*tag[p];
                h[p<<1]+=add,h2[p<<1]+=add,tag[p<<1]+=tag[p];
                add=pre[r-mid-1]*tag[p];
                h[p<<1|1]+=add,h2[p<<1|1]+=add,tag[p<<1|1]+=tag[p];
                tag[p]=0;
                return;
            }
            if(ql<=mid)self(self,p<<1,l,mid,ql,qr);
            if(qr>mid)self(self,p<<1|1,mid+1,r,ql,qr);
        };
        ull ans2;
        auto query2=[&](auto &&self,int p,int l,int r,int ql,int qr){
            if(ql<=l&&r<=qr){
                ans2=h2[p]+ans2*bs[r-l+1];
                return;
            }
            int mid=l+r>>1;
            if(tag[p]){
                ull add=pre[mid-l]*tag[p];
                h[p<<1]+=add,h2[p<<1]+=add,tag[p<<1]+=tag[p];
                add=pre[r-mid-1]*tag[p];
                h[p<<1|1]+=add,h2[p<<1|1]+=add,tag[p<<1|1]+=tag[p];
                tag[p]=0;
                return;
            }
            if(qr>mid)self(self,p<<1|1,mid+1,r,ql,qr);
            if(ql<=mid)self(self,p<<1,l,mid,ql,qr);
        };
        while(q--){
            int op;
            scanf("%d",&op);
            if(op&1){
                int l,r,v;
                scanf("%d%d%d",&l,&r,&v);
                modify(modify,1,0,n-1,l-1,r-1,v*2);
            }
            else{
                int k;
                scanf("%d",&k),--k;
                int ez=0,l=1,r=min(k,n-1-k);
                while(l<=r){
                    int mid=l+r>>1;
                    ans=ans2=0;
                    query(query,1,0,n-1,k-mid,k-1),query2(query2,1,0,n-1,k+1,k+mid);
                    if(ans+2*b*pre[mid-1]==ans2)ez=mid,l=mid+1;
                    else r=mid-1;
                }
                printf("%d\n",ez);
            }
        }
    }
    return 0;
}