#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 data{

	int l,r,x,b,z;

	data(int A=0,int B=0,int C=0,int D=0,int E=0):l(A),r(B),x(C),b(D),z(E){}

	bool operator < (const data &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){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");

	scanf("%d %d %d %d",&n,&m,&p1,&p2);

	a[0]=a[n+1]=n+1; S[top=1]=0;

	for(int i=1;i<=n+1;i++){

		if(i<=n) a[i]=getint();

		while(a[S[top]]<a[i]) ri[S[top--]]=i;

		le[i]=S[top]; S[++top]=i;

	}

	for(int i=1,l,r;i<=m;i++){

		l=getint(),r=getint(); ans[i]+=(r-l)*p1;

		s1[i]=data(l,r,l-1,i,-1);

		s1[i+m]=data(l,r,r,i,1);

	}

	sort(s1+1,s1+m*2+1);

	for(int i=1;i<=n;i++){

		if(le[i] && ri[i]<=n) s2[++ls]=data(le[i],le[i],ri[i],0,p1);

		if(le[i] && ri[i]>i+1) s2[++ls]=data(i+1,ri[i]-1,le[i],0,p2);

		if(ri[i]<=n && i>le[i]+1) s2[++ls]=data(le[i]+1,i-1,ri[i],0,p2);

	}

	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;

}