#include <stdio.h>

int main () {
  int n = 0;
  int i = 0;
  int s[1000] = {};
  int a[1000] = {};

  int res = 0;
  
  int dp[1001][1001] = {};
  int ans = 0;
  
  res = scanf("%d", &n);
  res = scanf("%d", &i);
  for (int j = 0; j < n; j++) {
    res = scanf("%d", s+j);
    res = scanf("%d", a+j);
  }
  
  for (int j = 0; j < n; j++) {
    for (int k = i; k >= 0; k--) {
      dp[j+1][k] = dp[j][k];
      if (k+s[j] <= i && dp[j+1][k+s[j]] < dp[j][k]+a[j]) {
        dp[j+1][k+s[j]] = dp[j][k]+a[j];
        if (dp[j+1][k+s[j]] > ans) {
          ans = dp[j+1][k+s[j]];
        }
      }
    }
  }
  
  printf("%d\n", ans);
  
  return 0;
}