#include<iostream>
#include<string>
#include<sstream>
#include<vector>

#pragma GCC optimize ("O3")
using namespace std;

int convertToMinutes(int time)
{
    int min = time % 10;
    time /= 10;
    min += (time % 10) * 10;
    time /= 10;
    min += (time % 10) * 60;
    time /= 10;
    min += (time % 10) * 600;
    return min;
}

int main()
{
    // Tweaks for faster cin execution
    std::cin.sync_with_stdio(false);
    std::cin.tie(nullptr);

    vector<int> bus_arrival_times;

    int time;
    string input_line;
    getline(cin >> ws, input_line);

    istringstream input_stream(input_line);

    while (input_stream && (input_stream >> time))
    {
        bus_arrival_times.push_back(convertToMinutes(time));
    }

    int train_time;

    cin >> ws >> train_time;

    train_time = convertToMinutes(train_time);

    int min_wait_time = 100000;
    for (int min : bus_arrival_times)
    {
        if (train_time < min)
        {
            continue;
        }

        if (train_time - min < min_wait_time)
        {
            min_wait_time = train_time - min;
        }
    }

    cout << min_wait_time << endl;
    return 0;
}