#include <bits/stdc++.h>
using namespace std;

int main() {
    int n;
    cin >> n;
    int cnt = 0;
    int m, p, q;
    cin >> m >> p >> q;
    int hard[12] = {};
    int crt = 1;
    for (int i = p; i < p + q; i++) {
        hard[i] = 1;
    }
    while (n > 0) {
        if (hard[crt]) {
            n -= 2 * m;
        } else {
            n -= m;
        }
        crt++;
        cnt++;
        if (crt == 13) {
            crt = 1;
        }
    }
    cout << cnt << endl;
}