/* -*- coding: utf-8 -*-
 *
 * 1861.cc:  No.1861 Required Number - yukicoder
 */

#include<cstdio>
#include<algorithm>
 
using namespace std;

/* constant */

const int MAX_N = 10000;
const int MAX_K = 1000;

/* typedef */

/* global variables */

int as[MAX_N];
bool dp0[MAX_N + 1][MAX_K + 1], dp1[MAX_N + 1][MAX_K + 1];

/* subroutines */

/* main */

int main() {
  int n, k;
  scanf("%d%d", &n, &k);
  for (int i = 0; i < n; i++) scanf("%d", as + i);

  dp0[0][0] = true;
  for (int i = 0; i < n; i++) {
    copy(dp0[i], dp0[i] + k + 1, dp0[i + 1]);
    for (int j = k - as[i]; j >= 0; j--)
      if (dp0[i][j]) dp0[i + 1][j + as[i]] = true;
  }

  if (! dp0[n][k]) { puts("-1"); return 0; }

  dp1[n][0] = true;
  for (int i = n - 1; i >= 0; i--) {
    copy(dp1[i + 1], dp1[i + 1] + k + 1, dp1[i]);
    for (int j = k - as[i]; j >= 0; j--)
      if (dp1[i + 1][j]) dp1[i][j + as[i]] = true;
  }

  int cnt = 0;
  for (int i = 0; i < n; i++) {
    bool found = false;
    for (int j = 0; ! found && j <= k; j++)
      found = (dp0[i][j] && dp1[i + 1][k - j]);

    if (! found) cnt++;
  }

  printf("%d\n", cnt);
  return 0;
}