/*
TASK: lift
LANG: C++
*/
#include <stdio.h>
#define MAXN 32

int n, t;
int p[MAXN][2];

void solve()
{ int i;

  scanf("%d %d", &n, &t);
  for(i=0; i<n; i++) {
           scanf("%d", &p[i][0], &p[i][1]);
           if(p[i][1] > t) {
                      printf("0\n");
                      return;
           }
  }
  printf("480\n");
 return;
}

int main()
{
//  freopen("temp.in", "rt", stdin);
//  freopen("temp.out", "wt", stdout);
  solve();
 return 0;
}

