#include <bits/stdc++.h>
using namespace std;

const int t[7][7] = {
	{0, 300, 500, 600, 700, 1350, 1650},
	{6, 0, 350, 450, 600, 1150, 1500},
	{13, 7, 0, 250, 400, 1000, 1350},
	{18, 12, 5, 0, 250, 850, 1300},
	{23, 17, 10, 5, 0, 600, 1150},
	{43, 37, 30, 25, 20, 0, 500},
	{58, 52, 45, 40, 35, 15, 0}
};

const int B = 17 * 60 + 30, E = 19 * 60 + 30;

int main()
{
	int id1, h1, m1;
	int id2, h2, m2;
	while (scanf("%d", &id1), id1){
		scanf("%d %d %d %d %d", &h1, &m1, &id2, &h2, &m2);
		if (id1 > id2) swap(id1, id2);
		int t1 = h1 * 60 + m1;
		int t2 = h2 * 60 + m2;
		--id1; --id2;
		int v = t[id1][id2];
		int l = t[id2][id1];
		bool f = true;
		if (l > 40) f = false;
		if (((B <= t1 && t1 <= E) || (B <= t2 && t2 <= E)) && f){
			v /= 2;
			int f = !!(v % 50);
			v = v / 50 * 50 + f * 50;
		}
		printf("%d\n", v);
	}
	return 0;
}