#include <bits/stdc++.h>   using namespace std;   int a, ta, b, tb, hh, mm, res1, res2;   int main() {     ios::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     cin >> a >> ta >> b >> tb;     char tmp;     cin >> hh >> tmp >> mm;     hh -= 5;     mm += hh * 60;     if (mm - tb >= 0) res1 = (mm - tb) / b + 1;     mm += ta;     mm = min(mm, (24 - 5) * 60);     mm--;     res2 = mm / b + 1;     cout << res2 - res1 << endl;   }   