【Codeforces Round #457 (Div. 2) A】 Jamie and Alarm Snooze

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

int hh,mm,x,cnt;

bool find7(){
    if (hh%10==7 || (hh/10)==7) return true;
    if (mm%10==7 || (mm/10)==7) return true;
    return false;
}

int main(){
    #ifdef LOCAL_DEFINE
        freopen("rush_in.txt", "r", stdin);
    #endif
    ios::sync_with_stdio(0),cin.tie(0);
    cin >> x;
    cin >> hh >> mm;
    while (!find7()){
        mm-=x;
        cnt++;
        if (mm<0){
            hh--;
            mm+=60;
            if (hh<0){
                hh = 23;
            }
        }
    }
    cout <<cnt<<endl;
    return 0;
}