#include <iostream>
using namespace std;

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

int main () {
	int a, b;
	while (cin >> a, a) {
		int h, m;
		bool half = false;
		cin >> h >> m;
		int s = h * 60 + m;
		if (17 * 60 + 30 <= s && s <= 19 * 60 + 30) half = true;
		cin >> b;
		cin >> h >> m;
		s = h * 60 + m;
		if (17 * 60 + 30 <= s && s <= 19 * 60 + 30) half = true;
		a--, b--;
		int price = p[a][b];
		int dist = d[a][b];
		if (dist <= 40 && half) price /= 2;
		cout << price + (price % 50) << endl;
	}
	return 0;
}