#include<iostream>
#include<stdio.h>
#include<stdlib.h>
#include<algorithm>
#include<vector>
#include<string.h>
#include<math.h>
#include<map>
#include<iomanip>
#include<queue>

using ll = long long;

using namespace std;

const int inf = 1e6 + 7;

int main(){	
	int a , b;
	cin >> a >> b;
	a %= 12;
	b %= 60;
	int second = 3600*a + 60*b;
	int ans = inf;
	for(int i = 0; i < 20; i++){
		int t = 3600*12*i/11 - second;
		if(t < 0)continue;
		ans = min(ans,t);
	}
	cout << ans << endl;	
	return 0;
}