#include <bits/stdc++.h>
using namespace std;
const int t[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}};
const int B = 17 * 60 + 30, E = 19 * 60 + 30;
int main() {
  int id1, h1, m1;
  int id2, h2, m2;
  while (scanf("%d", &id1), id1) {
    scanf("%d %d %d %d %d", &h1, &m1, &id2, &h2, &m2);
    if (id1 > id2) swap(id1, id2);
    int t1 = h1 * 60 + m1;
    int t2 = h2 * 60 + m2;
    --id1;
    --id2;
    int v = t[id1][id2];
    int l = t[id2][id1];
    bool f = true;
    if (l > 40) f = false;
    if (t2 < B) f = false;
    if (E < t1) f = false;
    if (!(t1 <= B ^ E <= t2)) f = false;
    if (f) {
      v /= 2;
      int f = !!(v % 50);
      v = v / 50 * 50 + f * 50;
    }
    printf("%d\n", v);
  }
  return 0;
}
