把时间都转化成秒即可；

#include<bits/stdc++.h>
using namespace std;
string a,b;
int main()
{
    cin>>a>>b;
    int cnt=0,sum=0;
    int k=((b[0]-'0')*10+(b[1]-'0'))*3600;
    int h=((a[0]-'0')*10+(a[1]-'0'))*3600;
    k+=((b[3]-'0')*10+(b[4]-'0'))*60;
    h+=((a[3]-'0')*10+(a[4]-'0'))*60;
    k+=(b[6]-'0')*10+(b[7]-'0');
    h+=(a[6]-'0')*10+(a[7]-'0');
    cout<<abs(h-k);
}