#include <bits/stdc++.h>
using namespace std;
int kiriage(int);
int main() {
  int tmp[7][7] = {
      {0, 300, 500, 600, 700, 1350},    {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 sIC, sh, sm, gIC, gh, gm, smin, gmin, cost;
  while (cin >> sIC && sIC) {
    cin >> sh >> sm >> gIC >> gh >> gm;
    smin = sh * 60 + sm;
    gmin = gh * 60 + gm;
    if (sIC > gIC) swap(sIC, gIC);
    cout << ((((smin >= 1050 && smin <= 1170) ||
               (gmin >= 1050 && gmin <= 1170)) &&
              tmp[gIC - 1][sIC - 1] <= 40)
                 ? kiriage(tmp[sIC - 1][gIC - 1] / 2)
                 : tmp[sIC - 1][gIC - 1])
         << endl;
  }
}
int kiriage(int cost) { return (cost % 50 == 0 ? cost : cost / 50 * 50 + 50); }
