import sys
input = sys.stdin.readline
#input = sys.stdin.buffer.readline #文字列はダメ
#sys.setrecursionlimit(1000000)
#import bisect
#import itertools
#import random
#from heapq import heapify, heappop, heappush
#from collections import defaultdict 
#from collections import deque
#import copy
#import math
#from functools import lru_cache
#@lru_cache(maxsize=None)
#MOD = pow(10,9) + 7
#MOD = 998244353
#dx = [1,0,-1,0]
#dy = [0,1,0,-1]

def main():
    N,K = map(int,input().split())
    A = list(map(int,input().split()))

    #dpl[i][j]:左からi番目まで見て和がjを作れるか0/1
    dpl = [[0]*(N+1) for _ in range(K+1)]
    dpl[0][0] = 1
    #dpr[i][j]:右からi番目まで見て和がjを作れるか0/1
    dpr = [[0]*(N+1) for _ in range(K+1)]
    dpr[0][0] = 1
    #配るDP
    for i in range(N):
        for j in range(K+1):
            #使わない
            dpl[j][i+1] |= dpl[j][i]
            #使う
            if j+A[i] <= K:
                dpl[j+A[i]][i+1] |= dpl[j][i]
        for j in range(K+1):
            #使わない
            dpr[j][i+1] |= dpr[j][i]
            #使う
            if j+A[N-1-i] <= K:
                dpr[j+A[N-1-i]][i+1] |= dpr[j][i]
    if dpl[K][N] == 0:
        print(-1);exit()

    #print(dpl)
    #print(dpr)
    ans = 0
    for i in range(N):
        for x in range(K+1):
            if dpl[x][i] == 1 and dpr[K-x][N-1-i] == 1:
                break
        else:
            ans += 1
    print(ans)

if __name__ == '__main__':
    main()