Jamie and Alarm Snooze

Jamie loves sleeping. One day, he decides that he needs to wake up at exactly hh: mm. However, he hates waking up, so he wants to make waking up less painful by setting the alarm at a lucky time. He will then press the snooze button every x minutes until hh: mm is reached, and only then he will wake up. He wants to know what is the smallest number of times he needs to press the snooze button.

A time is considered lucky if it contains a digit '7'. For example, 13: 07 and 17: 27 are lucky, while 00: 48 and 21: 34 are not lucky.

Note that it is not necessary that the time set for the alarm and the wake-up time are on the same day. It is guaranteed that there is a lucky time Jamie can set so that he can wake at hh: mm.

Formally, find the smallest possible non-negative integer y such that the time representation of the time x·y minutes before hh: mm contains the digit '7'.

Jamie uses 24-hours clock, so after 23: 59 comes 00: 00.

Input

The first line contains a single integer x (1 ≤ x ≤ 60).

The second line contains two two-digit integers, hh and mm (00 ≤ hh ≤ 23, 00 ≤ mm ≤ 59).

Output

Print the minimum number of times he needs to press the button.

Example
Input
3
11 23
Output
2
Input
5
01 07
Output
0
Note

In the first sample, Jamie needs to wake up at 11:23. So, he can set his alarm at 11:17. He would press the snooze button when the alarm rings at 11:17 and at 11:20.

In the second sample, Jamie can set his alarm at exactly at 01:07 which is lucky.

代码:

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
using namespace std;
int check(int hh,int mm)
{
    if(hh % 10 == 7 || mm % 10 == 7)return 1;
    return 0;
}
int main()
{
    int x,hh,mm,c = 0;
    cin>>x>>hh>>mm;
    while(!check(hh,mm))
    {
        c ++;
        if(mm < x)
        {
            mm += 60 - x;
            if(hh == 0)hh = 23;
            else hh --;
        }
        else mm -= x;
    }
    cout<<c;
}
原文地址:https://www.cnblogs.com/8023spz/p/8358410.html