UVa 11677 - Alarm Clock

#include <bits/stdc++.h>
#define LL  long long
#define SZ(x) ((int)(x).size())
#define ALL(x) (x).begin(),(x).end()
#define REP(i,n) for(int i=0;i<n;i++)
#define REV(i,n) for(int i=n-1;i>=0;i--)
#define FOR(i,a,b) for(int i=a;i<=b;i++)
#define pri(a) cout<<a<<endl
#define prii(a,b) cout<<a<<" "<<b<<endl
#define priii(a,b,c) cout<<a<<" "<<b<<" "<<c<<endl
#define hi printf("Hello World\n");
#define pcs printf("CASE# %d:\n", ++cs);
#define WRITE(fn) freopen(fn, "w", stdout);
using namespace std;

/****/ int cs = 0;
const int INF = 1<<29;
const int MX  = 1e5+10;

int main()
{
    int h,m,hh,mm;

    while(cin>>h>>m>>hh>>mm and h+hh+m+mm)
    {
        int t = h*60 + m;
        int tt = hh*60 + mm;

        int ans = tt - t;

        if(ans <= 0) ans += 1440;

        ans %= 1440;

        pri(ans);
    }

    return 0;
}