#include <bits/stdc++.h>
using namespace std;
int p, x, y;
queue<int> q;
int mmap[100000];
bool check(int s) {
  int i = s / 50 % 475;
  for (int j = 0; j < 25; ++j) {
    i = (i * 96 + 42) % 475;
    if (26 + i == p) return true;
  }
  mmap[s] = 1;
  return false;
}
int main() {
  cin >> p >> x >> y;
  q.push(0);
  while (!q.empty()) {
    int n = q.front();
    q.pop();
    int s = x + n * 100;
    while (s >= y) {
      if (mmap[s]) {
        s -= 50;
        continue;
      }
      if (check(s)) {
        cout << n << endl;
        return 0;
      }
      s -= 50;
    }
    q.push(n + 1);
  }
  return 0;
}
