#include <stdio.h>
#include <vector>
#include <algorithm>
#include <math.h>
#include <queue>

using namespace std;

int main(){

	int start,goal,start_h,start_m,goal_h,goal_m,ans;
	int dist[8] = {0,0,6,13,18,23,43,58},toll[8][8];
	toll[1][1] = 0,toll[1][2] = 300,toll[1][3] = 500,toll[1][4] = 600,toll[1][5] = 700,toll[1][6] = 1350,toll[1][7] = 1650;
	toll[2][2] = 0,toll[2][3] = 350,toll[2][4] = 450,toll[2][5] = 600,toll[2][6] = 1150,toll[2][7] = 1500;
	toll[3][3] = 0,toll[3][4] = 250,toll[3][5] = 400,toll[3][6] = 1000,toll[3][7] = 1350;
	toll[4][4] = 0,toll[4][5] = 250,toll[4][6] = 850,toll[4][7] = 1300;
	toll[5][5] = 0,toll[5][6] = 600,toll[5][7] = 1150;
	toll[6][6] = 0,toll[6][7] = 500;

	while(true){
		scanf("%d",&start);
		if(start == 0)break;

		scanf("%d %d",&start_h,&start_m);

		scanf("%d",&goal);
		scanf("%d %d",&goal_h,&goal_m);

		ans = toll[start][goal];

		if(dist[goal]-dist[start] <= 40){
			if((start_h*60+start_m) >= 17*60+30 || (goal_h*60+goal_m) <= 19*60+30){
				ans /= 2;
				if(ans%50 > 0){
					while(ans % 50 != 0)ans++;
				}
			}
		}

		printf("%d\n",ans);

	}

    return 0;
}