#include <iostream>
#include <cmath>
using namespace std;

int dist[] = {0, 6, 13, 18, 23, 43, 58};
int cost[][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 main() {
	int s, g;
	while(cin >> s, s) {
		int h, m;
		bool half = false;
		cin >> h >> m;
		if(17 * 60 + 30 <= h * 60 + m && h * 60 + m <= 18 * 60 + 30)
			half = true;
		cin >> g >> h >> m;
		if(17 * 60 + 30 <= h * 60 + m && h * 60 + m <= 18 * 60 + 30)
			half = true;

		half &= abs(dist[s-1] - dist[g-1]) <= 40;

		if(half)
			cout << ((cost[s-1][g-1] / 50) + 1) / 2 * 50 << endl;
		else
			cout << cost[s-1][g-1] << endl;
	}
}