#include<bits/stdc++.h>
#define LL long long
#define rep(i,a,b) for(int i=a,i##end=b;i<=i##end;++i)
#define drep(i,a,b) for(int i=a,i##end=b;i>=i##end;--i)
#define erep(i,a) for(int i=head[a];i;i=e[i].nxt)
using namespace std;
const int M=2e5+5;

int n,m,k,b,a[M];
const int N=2;
const LL P[]={998244353,(LL)1e9+7};
struct node{
    LL h[N];
    node (){memset(h,0,sizeof(h));}
    void calc(LL x){
        rep(i,0,N-1)h[i]=x;
    }
    node operator + (const LL &_)const{
        node r;
        rep(i,0,N-1)r.h[i]=(h[i]+_)%P[i];
        return r;
    }
    node operator + (const node &_)const{
        node r;
        rep(i,0,N-1)r.h[i]=(h[i]+_.h[i])%P[i];
        return r;
    }
    node operator * (const LL &_)const{
        node r;
        rep(i,0,N-1)r.h[i]=h[i]*_%P[i];
        return r;
    }
    node operator * (const node &_)const{
        node r;
        rep(i,0,N-1)r.h[i]=h[i]*_.h[i]%P[i];
        return r;
    }
    bool operator == (const node &_)const{
        rep(i,0,N-1)if(h[i]^_.h[i])return 0;
        return 1;
    }
}T[M],E[M],B;
void init(){
    B.h[0]=2e8+3;
    B.h[1]=2e8+7;
    int n=2e5;
    T[0].calc(1);
    rep(i,1,n)T[i]=T[i-1]*B;
    rep(i,1,n)E[i]=E[i-1]+T[i-1];
}
#define lp p<<1
#define rp p<<1|1
struct Seg{
    int len[M<<2];
    node t[M<<2];
    LL c[M<<2];
    void up(int w,int p){
        if(w)t[p]=t[lp]+t[rp]*T[len[lp]];
        else t[p]=t[lp]*T[len[rp]]+t[rp];
    }
    void down(int p){
        if(!c[p])return;
        t[lp]=t[lp]+E[len[lp]]*c[p];c[lp]+=c[p];
        t[rp]=t[rp]+E[len[rp]]*c[p];c[rp]+=c[p];
        c[p]=0;
    }
    void build(int w,int l=1,int r=n,int p=1){
        len[p]=r-l+1;
        if(l==r){
            if(w)t[p].calc(2*a[l]-k*l);
            else t[p].calc(2*a[l]-k*l+2*b);
            return;
        }
        int mid=(l+r)>>1;
        build(w,l,mid,lp);
        build(w,mid+1,r,rp);
        up(w,p);
    }
    void chg(int x,int y,int z,int w,int l=1,int r=n,int p=1){
        if(l==x && r==y){
            t[p]=t[p]+E[len[p]]*z;c[p]+=z;
            return;
        }
        int mid=(l+r)>>1;down(p);
        if(y<=mid)chg(x,y,z,w,l,mid,lp);
        else if(mid<x)chg(x,y,z,w,mid+1,r,rp);
        else chg(x,mid,z,w,l,mid,lp),chg(mid+1,y,z,w,mid+1,r,rp);
        up(w,p);
    }
    node qry(int x,int y,int w,int l=1,int r=n,int p=1){
        if(l==x && r==y)return t[p];
        int mid=(l+r)>>1;down(p);
        if(y<=mid)return qry(x,y,w,l,mid,lp);
        if(mid<x)return qry(x,y,w,mid+1,r,rp);
        if(w)return qry(x,mid,w,l,mid,lp)+qry(mid+1,y,w,mid+1,r,rp)*T[mid-x+1];
        else return qry(x,mid,w,l,mid,lp)*T[y-mid]+qry(mid+1,y,w,mid+1,r,rp);
    }
}T1,T0;

bool chk(int x,int r){
    return T1.qry(x+1,x+r,1)==T0.qry(x-r,x-1,0);
}
int main(){
    init();
    scanf("%d%d%d%d",&n,&m,&k,&b);
    rep(i,1,n)scanf("%d",&a[i]);
    T1.build(1);
    T0.build(0);
    rep(i,1,m){
        int op,x,y,z;
        scanf("%d",&op);
        if(op==1){
            scanf("%d%d%d",&x,&y,&z);z<<=1;
            T1.chg(x,y,z,1);
            T0.chg(x,y,z,0);
        }
        if(op==2){
            scanf("%d",&x);
            int l=1,r=min(n-x,x-1);
            while(l<=r){
                int mid=(l+r)>>1;
                if(chk(x,mid))l=mid+1;
                else r=mid-1;
            }
            printf("%d\n",r);
        }
    }
    return 0;
}
/*
3
0 1 2
1 2 3
2 3 4

*/