#include<iostream>
using namespace std;
int s[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}};

int main(){
  int sc,sh,sm,ec,eh,em; 
  while(cin>>sc&&sc){
    cin>>sh>>sm>>ec>>eh>>em;
    int an=s[sc-1][ec-1],S=sh*100+sm,E=eh*100+em;
    if(S>E)E+=2400;
    if(s[ec-1][sc-1]<=40&&
       ((1930<S&&E<1730+2400&&E<1930+2400)||
	(S<1730&&1730<E&&E<1930)||
	(1730<S&&S<1930&&1930<E&&E<1730+2400)||
	(S==1730&&1730<E&&E<1930)||
	(S==1930&&1930<E&&E<1730+2400)||
	(E==1730&&S<1730)||
	(E==1930&&1730<S&&S<1930)||
	(E==1730+2400&&1930<S)))an/=2;
    if(an%50)an-=an%50,an+=50;
    cout<<an<<endl;
  }
  return 0;
}