#include<bits/stdc++.h>
using namespace std;
int f(int d,int h,int m){int t=((d-23)*24+h)*60+m;if(d>29||(d==29&&h>=3))t-=60;return t;}int main(){ios::sync_with_stdio(false);cin.tie(nullptr);int x,d,h,m;cin>>x>>d>>h>>m;int e[]={0,25,26,27,28,30};cout<<f(e[x],0,0)-f(d,h,m)<<'\n';return 0;}