#include <iostream>
#include <cstdio>
#include <queue>
using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
const int N = 100010;
int n; ll X, Y, Z;
int a[N], b[N];
namespace subtask2 {
    priority_queue<pii, vector<pii>, greater<pii>> q;
    void main() {
//        printf("In sub2:\n");
        for (int i = 1; i <= n; i++) 
            if(a[i] > b[i]) q.push({i, a[i] - b[i]});
        ll eps1 = 0, eps2 = 0, ans = 0;
        for (int i = 1; i <= n; i++) {
            if(a[i] >= b[i]) continue;
            ll delta = b[i] - a[i];
            while(q.size() && q.top().second <= delta) {
                delta -= q.top().second;
                ans += 1ll * abs(i - q.top().first) * q.top().second;
                q.pop();
            }
            if(delta && q.size()) {
                pii pr = q.top(); q.pop();
                ans += 1ll * abs(i - pr.first) * delta;
                q.push({pr.first, pr.second - delta});
                delta = 0;
            }
            if(delta) eps1 += delta;
        }
        while(q.size()) eps2 += q.top().second, q.pop();
        if(eps1) ans += X * eps1;
        if(eps2) ans += Y * eps2;
        printf("%lld\n", ans);
    }
}

int main() {
    scanf("%d%lld%lld%lld", &n, &X, &Y, &Z);
    for (int i = 1; i <= n; i++) scanf("%d%d", &a[i], &b[i]);
    /*if(X == Y && X == 1e8 && Z == 1)*/ subtask2::main();
    return 0;
}