#include <bits/stdc++.h>
using namespace std;
int main() {
  int discount[2] = {17 * 60 + 30, 19 * 60 + 30};
  int D[7] = {0, 6, 13, 18, 23, 43, 58};
  int C[7][7] = {
      {0, 300, 500, 600, 700, 1350, 1650}, {0, 0, 350, 450, 600, 1150, 1500},
      {0, 0, 0, 250, 400, 1000, 1350},     {0, 0, 0, 0, 250, 850, 1300},
      {0, 0, 0, 0, 0, 600, 1150},          {0, 0, 0, 0, 0, 0, 500},
  };
  int in, out;
  while (cin >> in, in) {
    int h1, m1, h2, m2, fare;
    cin >> h1 >> m1;
    cin >> out;
    cin >> h2 >> m2;
    if (in > out) {
      int tmp = in;
      in = out;
      in = tmp;
    }
    int d = D[out - 1] - D[in - 1];
    int min1 = h1 * 60 + m1;
    int min2 = h2 * 60 + m2;
    if ((discount[0] <= min1 && min1 <= discount[1]) ||
        (discount[0] <= min2 && min2 <= discount[1]) && d <= 40)
      fare = (C[in - 1][out - 1] / 2 + 25) / 50 * 50;
    else
      fare = C[in - 1][out - 1];
    cout << fare << endl;
  }
  return 0;
}
