#include <bits/stdc++.h>
#define N 200011
using namespace std;
int n,q,k,b,a[N];
const int P[2]={1028838407,1013333903};
struct mint{int x[2];mint(){x[0]=x[1]=0;}mint(int _x){x[0]=_x;x[1]=_x;}mint(int _a,int _b){x[0]=_a;x[1]=_b;}};
mint operator+(mint a,mint b){return mint((a.x[0]+b.x[0])%P[0],(a.x[1]+b.x[1])%P[1]);}
mint operator-(mint a,mint b){return mint((a.x[0]+P[0]-b.x[0])%P[0],(a.x[1]+P[1]-b.x[1])%P[1]);}
mint operator*(mint a,mint b){return mint(1ll*a.x[0]*b.x[0]%P[0],1ll*a.x[1]*b.x[1]%P[1]);}
bool operator==(mint a,mint b){return a.x[0]==b.x[0]&&a.x[1]==b.x[1];}
mint pw[N],spw[N];
const int B=801801801;
mint lsum[N*4],rsum[N*4];
void pushup(int x,int L,int R)
{
	int M=L+R>>1;
	lsum[x]=lsum[x<<1]*pw[R-M]+lsum[x<<1|1];
	rsum[x]=rsum[x<<1]+rsum[x<<1|1]*pw[M-L+1];
}
int tag[N*4];
void apply(int x,int p,int L,int R)
{
	lsum[x]=lsum[x]+p*spw[R-L];
	rsum[x]=rsum[x]+p*spw[R-L];
	tag[x]+=p;
}
void pushdown(int x,int L,int R)
{
	if(tag[x])
	{
		apply(x<<1,tag[x],L,L+R>>1);
		apply(x<<1|1,tag[x],(L+R>>1)+1,R);
		tag[x]=0;
	}
}
void build(int L,int R,int x)
{
	if(L==R){lsum[x]=rsum[x]=mint((a[L]-(k/2)*L+P[0])%P[0],(a[L]-(k/2)*L+P[1])%P[1]);return;}
	build(L,L+R>>1,x<<1);build((L+R>>1)+1,R,x<<1|1);pushup(x,L,R);
}
mint lquery(int l,int r,int L,int R,int x)
{
	if(l<=L&&R<=r)return lsum[x];pushdown(x,L,R);
	if(l<=L+R>>1&&r>L+R>>1)
	{
		mint lv=lquery(l,r,L,L+R>>1,x<<1);
		mint rv=lquery(l,r,(L+R>>1)+1,R,x<<1|1);
		return lv*pw[min(r,R)-(L+R>>1)]+rv;
	}
	if(l<=L+R>>1)return lquery(l,r,L,L+R>>1,x<<1);return lquery(l,r,(L+R>>1)+1,R,x<<1|1);
}
mint rquery(int l,int r,int L,int R,int x)
{
	if(l<=L&&R<=r)return rsum[x];pushdown(x,L,R);
	if(l<=L+R>>1&&r>L+R>>1)
	{
		mint lv=lquery(l,r,L,L+R>>1,x<<1);
		mint rv=lquery(l,r,(L+R>>1)+1,R,x<<1|1);
		return rv*pw[(L+R>>1)-max(l,L)+1]+lv;
	}
	if(l<=L+R>>1)return rquery(l,r,L,L+R>>1,x<<1);return rquery(l,r,(L+R>>1)+1,R,x<<1|1);
}
void add(int l,int r,int p,int L,int R,int x)
{
	if(l<=L&&R<=r){apply(x,p,L,R);return;}pushdown(x,L,R);
	if(l<=L+R>>1)add(l,r,p,L,L+R>>1,x<<1);if(r>L+R>>1)add(l,r,p,(L+R>>1)+1,R,x<<1|1);pushup(x,L,R);
}
int main()
{
	scanf("%d%d%d%d",&n,&q,&k,&b);
	for(int i=1;i<=n;++i)scanf("%d",a+i),a[i]*=2;
	pw[0]=1;for(int i=1;i<N;++i)pw[i]=pw[i-1]*B;
	spw[0]=1;for(int i=1;i<N;++i)spw[i]=spw[i-1]+pw[i];
	k*=2;b*=2;
	build(1,n,1);
	while(q--)
	{
		int cmd;
		scanf("%d",&cmd);
		if(cmd==1)
		{
			int l,r,v;scanf("%d%d%d",&l,&r,&v);v*=2;
			add(l,r,v,1,n,1);
		}
		else
		{
			int i;scanf("%d",&i);
			int L=1,R=min(i-1,n-i),ans=0;
			while(L<=R)
			{
				int M=L+R>>1;
				// printf("[%d,%d]:{%d,%d} [%d,%d]:{%d,%d}\n",i-M,i-1,lquery(i-M,i-1,1,n,1).x[0],lquery(i-M,i-1,1,n,1).x[1],i+1,i+M,rquery(i+1,i+M,1,n,1).x[0],rquery(i+1,i+M,1,n,1).x[1]);
				if(lquery(i-M,i-1,1,n,1)+b*spw[M-1]==rquery(i+1,i+M,1,n,1))ans=M,L=M+1;else R=M-1;
			}
			printf("%d\n",ans);
		}
	}
	fclose(stdin);fclose(stdout);return 0;
}