#include <bits/stdc++.h>

using namespace std;

int howManyGames(int p, int d, int m, int s)
{
    // Return the number of games you can buy
    int a[11]={20,17,14,11,8,6,6,6,6,6,6};
    int sum=0,i;
    for(i=0;i<m;i++);
    {
        sum=sum+a[i];
    }
    if(sum<=s)
    {
        return m;
    }
    else if(s<=85)
    {
        return 7;
    }
    else if(s<=91)
    {
        return 8;
    }
    else if(s<=97)
        
    {
        return 9;
    }
    else 
    {
        return 10;
    }
    
}

int main() {
    int p;
    int d;
    int m;
    int s;
    cin >> p >> d >> m >> s;
    int answer = howManyGames(p, d, m, s);
    cout << answer << endl;
    return 0;
}