#include <bits/stdc++.h>
using namespace std;
int main() {
  int d[7][7] = {
      {-1, 300, 500, 600, 700, 1350, 1650}, {6, -1, 350, 450, 600, 1150, 1500},
      {13, 7, 0, 250, 400, 1000, 1350},     {18, 12, 5, 0, 250, 850, 1300},
      {23, 17, 10, 5, -1, 600, 1150},       {43, 37, 30, 25, 20, -1, 500},
      {58, 52, 45, 40, 35, 15, -1}};
  int s, t, hs, ms, ht, mt;
  while (cin >> s, s) {
    cin >> hs >> ms >> t >> ht >> mt;
    ms += hs * 60;
    mt += ht * 60;
    s--, t--;
    bool flg = false;
    if ((17 * 60 + 30 <= ms && ms <= 19 * 60 + 30) ||
        (17 * 60 + 30 <= mt && mt <= 19 * 60 + 30))
      flg = true;
    int price = d[s][t];
    if (d[t][s] <= 40 && flg) {
      price /= 2;
    }
    cout << price << endl;
  }
  return 0;
}
