#include<bits/stdc++.h>
using namespace std;
int n,q,s,t,a[2010],b[2010];
int main(){
    freopen("foehn.in","r",stdin);
    freopen("foehn.out","w",stdout);
    cin>>n>>q>>s>>t;
    for(int i=0;i<=n;i++){
        cin>>a[i];
    }
    while(q--){
        int x,y,z;
        cin>>x>>y>>z;
        for(int i=x;i<=y;i++){
            a[i]=a[i]+z;
        }
        for(int i=1;i<=n;i++){
            if(a[i]>a[i-1]){
                b[i]=b[i-1]-s*(a[i]-a[i-1]);
            }
            if(a[i]<a[i-1]){
                b[i]=b[i-1]+t*(a[i-1]-a[i]);
            }
        }
        cout<<b[n]<<endl;
    }
    return 0;
}