#include <bits/stdc++.h>
using namespace std;
int main(){
    int a, b;
    cin >> a >> b;
    if(a > 25 || b < 23){
        cout << 3 << endl;
        return 0;
    }
    if(a < 23){
        if(b > 25){
            cout << 0 << endl;
            return 0;
        }
        if(b < 23){
            cout << 3 << endl;
            return 0;
        }
        cout << 25 - b << endl;
        return 0;
    }
    if(b > 25){
        if(a > 25){
            cout << 3 << endl;
        }
        else    cout << a - 23 << endl;
    }
    else{
        if(a < 23){
            cout << 25 - b << endl;
        }
        else{
            cout << (a - 23) + (25 - b) << endl;
        }
    }
}