#include <iostream>
#include <cmath>
using namespace std;
 
int main() {
	long long h1, m1, h2, m2, sum, sum1=0, sum2=0, res1=0, res2=0;
	char a;
	cin >> h1 >> a >> m1 >> h2 >> a >> m2;
	sum1=h1*60+m1;
	sum2=h2*60+m2;
	sum=(1440+(sum2-sum1))%1440; //количество минут между 1 и 2 временем учитывая переход через полночь
	sum2=sum1+sum;
	double r;
	r=(h1%12+m1/12.0+1);//12:00 и 00:00
	res1=sum1*11/720+ceil((r-1)/r);
	res2=sum2*11/720+1;
	cout << res2-res1;
	return 0;
}

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

MDA6MDAKMTI6MDE=

00:00
12:01