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

int main(){
  int aa[8][8]={ {0,1,2,3,4,5,6,7},
                 {1,0,300,500,600,700,1350,1650},
		 {2,300,0,350,450,600,1150,1500},
	         {3,500,350,0,250,400,1000,1350},
	       	 {4,600,450,250,0,250,850,1300},
	       	 {5,700,600,400,250,0,600,1150},
	       	 {6,1350,1150,1000,850,600,0,500},
	       	 {7,1650,1500,1350,1300,1150,500,0}};
  int bb[8][8]={ {0,1,2,3,4,5,6,7},
		 {1,0,6,13,18,23,43,58},
		 {2,6,0,7,12,17,37,52},
		 {3,13,7,0,5,10,30,45},
		 {4,18,12,5,0,5,25,40},
		 {5,23,17,10,5,0,20,35},
		 {6,43,37,30,25,20,0,15},
		 {7,58,52,45,40,35,15,0}};

  int i,j,n,time00,time01,time10,time11,n2,disc,mo;
  int disc2;
  while(1){
    disc2=0;
    disc=0; //flag
    cin >> n;
    if(n == 0)break;
    cin >> time00 >> time01;
    cin >> n2;
    cin >> time10 >> time11;

   
    if((time10 == 19 && time11 <= 30) || (time00 == 19 && time01 <=30)){disc2=1;}
      else if(time00 == 18 || time10 == 18)disc2=1;
      else if((time10 == 17 && time11>=30) || (time00 == 17 && time01 >=30))disc2=1;
      if(bb[n2][n]<=40 && disc2==1)disc=1; 
   

    mo=aa[n][n2];
    if(disc == 1){
      mo=mo/2;
      disc=0;
      disc2=0;
       if(mo%50 !=0)mo=(mo-(mo%50))+50;
    }
    cout << mo << endl;


    }
  return 0;

}