#include <iostream>
#include <cstring>
#include <algorithm>
#define int long long
using namespace std;
const int N = 1e5+10;
int a[N],b[N],c[N];
int n,Z,X,Y,ans;
void solve(int i,bool vis[]){
    if(vis[i])return;
    //cout<<c[i]<<'\n';
    vis[i]=1;
    int j=1;
    while(j<=max(i,n-i-1)&&c[i]>0&&Z*j<X+Y){
        if(j<=n-i-1&&c[j+i]<0){
            int cc=min(-c[j+i],c[i]);
            ans+=Z*j*cc;
            c[i]-=cc;
            c[j+i]+=cc;
            vis[i+j]=1;
        }
        if(j<=i&&c[i-j]<0){
            int cc=min(-c[i-j],c[i]);
            ans+=Z*j*cc;
            c[i]-=cc;
            c[i-j]+=cc;
            vis[i-j]=1;
        }
        if(j<=n-i-1&&c[j+i]==0){
            solve(i+j,vis);
        }
        if(j<=i&&c[i-j]==0){
            solve(i-j,vis);
        }
        j++;
    }
    vis[i]=0;
    return;
}
bool tvis[N];
signed main()
{
    cin.tie(0);
    cout.tie(0);
    ios::sync_with_stdio(0);
    cin>>n>>X>>Y>>Z;
    int S=X+Y;
    for (int i = 0; i < n; i ++ ){
        cin>>a[i]>>b[i];
        c[i]=a[i]-b[i];
    }
    for (int i = 0; i < n; i ++ ) solve(i,tvis);
    //cout<<ans;
    for (int i = 0; i < n; i ++ ){
        if(c[i]<0)ans+=X*(-c[i])//,cout<<c[i];
        ;
        if(c[i]>0)ans+=Y*c[i]//,cout<<c[i];
        ;
        //cout<<' ';
    }
    cout<<ans;
}