#include <bits/stdc++.h>
using namespace std;
int a[110];
int l, r;
int n;
int sum;
int s1, s2;
int main() {
    cin >> n;
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        sum += a[i];
       
    }
     cin >> l >> r;
        if (sum < l * n || sum > r * n) {
            printf("-1");
            exit(0);
    }
    for (int i = 1; i <= n; i++){
        if (a[i] > r) s1 += a[i] - r;
        if (a[i] < l) s2 += l - a[i];
    }
    cout << max(s1, s2);
    return 0;
}