#include <cstdio>
#include <deque>
using namespace std;
struct node {
    int opt, x;
};
deque<node> dq;
int n;
long long x, y, z, ans;
int a[100010], b[100010];
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]);
        while (!dq.empty() && z * (i - dq.front().x) > x + y) {
            if (dq.front().opt == 1) {
                ans += y;
            } else {
                ans += x;
            }
            dq.pop_front();
        }
        while (a[i] < b[i] && !dq.empty() && dq.back().opt == 1) {
            a[i]++;
            ans += z * (i - dq.back().x);
            dq.pop_back();
        }
        while (a[i] > b[i] && !dq.empty() && dq.back().opt == -1) {
            a[i]--;
            ans += z * (i - dq.back().x);
            dq.pop_back();
        }
        while (a[i] < b[i]) {
            a[i]++;
            dq.push_back((node){-1, i});
        }
        while (a[i] > b[i]) {
            a[i]--;
            dq.push_back((node){1, i});
        }
    }
    while (!dq.empty()) {
        if (dq.front().opt == 1) {
            ans += y;
        } else {
            ans += x;
        }
        dq.pop_front();
    }
    printf("%lld\n", ans);
    return 0;
}