#include<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<map>
#define all(x) x.begin(),x.end()
#define pb push_back
#define ll long long 
#define P pair<int,int>
#define LP pair<ll,ll>
using namespace std;
int main() {
	int a, b;
	cin >> a>>b;
	if (b < 23) cout << 3 << endl;
	else if (b < 26) {
		if (a < 23) cout << 25 - b;
		else if (a < 26)b - a + 1;
		else cout << 0;
	}
	else {
		if (a < 23) cout << 3;
		else if (a < 26)25 - a + 1;
		else cout << 0;
	}
	return 0;
}