#include<bits/stdc++.h>
#define ls(p) p<<1
#define rs(p) p<<1|1
#define ull unsigned long long
const  ull base=998244353;
using namespace std;

const int N=2e5+5;
ull mi[N];
int n,q,B,k,a[N],b[N];
struct A{
	ull c[N<<2];
	void up(int p) {
		c[p]=c[ls(p)]+c[rs(p)];
	}
	void add(int p,int l,int r,int x,int y) {
		if(l==r) {
			c[p]+=y*mi[x];
			return;
		}
		int mid=l+r>>1;
		if(x<=mid) add(ls(p),l,mid,x,y);
			else add(rs(p),mid+1,r,x,y);
		up(p);
	}
	ull ask(int p,int l,int r,int x,int y) {
		if(l==x&&r==y) return c[p];
		int mid=l+r>>1;
		if(y<=mid) return ask(ls(p),l,mid,x,y);
		if(x>mid) return ask(rs(p),mid+1,r,x,y);
		return ask(ls(p),l,mid,x,mid)+ask(rs(p),mid+1,r,mid+1,y);
	}
}t1,t2;

bool check(int i,int mid) {
	return mi[n-i]*t1.ask(1,1,n,i+2,i+mid)==mi[i]*t2.ask(1,1,n,n-i+2,n-i+mid);
}
int main(){
	//freopen("1.in","r",stdin);
	//freopen("1.out","w",stdout);
	scanf("%d%d%d%d",&n,&q,&k,&B);
	for(int i=1;i<=n;++i) scanf("%d",&a[i]);
	mi[0]=1;
	for(int i=1;i<=n;++i) {
		mi[i]=mi[i-1]*base;
	}
	for(int i=1;i<=n;++i) {
		b[i]=a[i]-a[i-1];
		t1.add(1,1,n,i,b[i]);
		t2.add(1,1,n,n-i+1,k-b[i]);
	}
	while(q--) {
		int op; scanf("%d",&op);
		if(op==1) {
			int l,r,v; scanf("%d%d%d",&l,&r,&v);
			b[r+1]-=v; t1.add(1,1,n,r+1,-v);
			t2.add(1,1,n,n-r,v);
			b[l]+=v; t1.add(1,1,n,l,v);
			t2.add(1,1,n,n-l+1,-v);
		} else {
			int i; scanf("%d",&i);
			if(n==i||i==1||b[i+1]+b[i]!=B+k) {
				puts("0");
				continue;
			} else {
				int l=2,r=min(n-i,i-1),ans=1;
				while(l<=r) {
					int mid=l+r>>1;
					if(check(i,mid)) l=mid+1;
						else r=mid-1;
				}
				printf("%d\n",r);
			}
		}
	}
}