#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
#define File(s) freopen(s".in","r",stdin),freopen(s".out","w",stdout)
#define maxn 200010

using namespace std;
typedef long long llg;

struct Segment{
	int l,r,x,b,z;
	bool operator < (const Segment &h)const{return x<h.x;}
}s1[maxn<<1],s2[maxn*3];
int n,m,p1,p2,S[maxn],top,ls;
int a[maxn],le[maxn],ri[maxn];
llg ans[maxn],c1[maxn],c2[maxn];

int getint(){
	int w=0;bool q=0;
	char c=getchar();
	while((c>‘9‘||c<‘0‘)&&c!=‘-‘) c=getchar();
	if(c==‘-‘) c=getchar(),q=1;
	while(c>=‘0‘&&c<=‘9‘) w=w*10+c-‘0‘,c=getchar();
	return q?-w:w;
}

void add(int x,int y){if(x)for(int i=x;i<=n;i+=i&(-i)) c1[i]+=y,c2[i]+=1ll*x*y;}
llg sum(int x){
	llg t=0;
	for(int i=x;i;i-=i&(-i)) t+=(x+1)*c1[i]-c2[i];
	return t;
}

int main(){
	File("sf");
	n=getint(),m=getint(),p1=getint(),p2=getint();
	for(int i=1;i<=n;i++) a[i]=getint();
	a[0]=a[n+1]=n+1; S[top=1]=0;
	for(int i=1;i<=n;i++){
		while(a[S[top]]<a[i]) top--;
		le[i]=S[top]; S[++top]=i;
	}
	S[top=1]=n+1;
	for(int i=n;i>=1;i--){
		while(a[S[top]]<a[i]) top--;
		ri[i]=S[top]; S[++top]=i;
	}
	for(int i=1,l,r;i<=m;i++){
		l=getint(),r=getint(); ans[i]+=1ll*(r-l)*p1;
		s1[i].l=l,s1[i].r=r,s1[i].x=l-1;
		s1[i].b=i,s1[i].z=-1; s1[i+m]=s1[i];
		s1[i+m].x=r,s1[i+m].z=1;
	}
	sort(s1+1,s1+m*2+1);
	for(int i=1;i<=n;i++){
		if(le[i] && ri[i]<=n){
			ls++; s2[ls].x=ri[i]; s2[ls].z=p1;
			s2[ls].l=s2[ls].r=le[i];
		}
		if(le[i] && ri[i]>i+1){
			ls++; s2[ls].x=le[i]; s2[ls].z=p2;
			s2[ls].l=i+1,s2[ls].r=ri[i]-1;
		}
		if(ri[i]<=n && i>le[i]+1){
			ls++; s2[ls].x=ri[i]; s2[ls].z=p2;
			s2[ls].l=le[i]+1,s2[ls].r=i-1;
		}
	}
	sort(s2+1,s2+ls+1); int n1=1,n2=1;
	while(!s1[n1].x) n1++;
	for(int i=1;n1<=m*2 && i<=n;i++){
		while(n2<=ls && s2[n2].x==i){
			add(s2[n2].r+1,-s2[n2].z);
			add(s2[n2].l,s2[n2].z),n2++;
		}
		while(n1<=m*2 && s1[n1].x==i){
			ans[s1[n1].b]+=s1[n1].z*(sum(s1[n1].r)-sum(s1[n1].l-1));
			n1++;
		}
	}
	for(int i=1;i<=m;i++) printf("%lld\n",ans[i]);
	return 0;
}