import sys
input = sys.stdin.readline
from collections import *

N, K = map(int, input().split())
A = list(map(int, input().split()))
dp1 = [False]*(K+1)
dp1[0] = True
dp2 = [[False]*(K+1) for _ in range(N+1)]
dp2[0][0] = True

for i in range(N):
    for j in range(K+1):
        if dp2[i][j]:
            dp2[i+1][j] = True
            
            if j+A[N-1-i]<=K:
                dp2[i+1][j+A[N-1-i]] = True

if not dp2[N][K]:
    exit(print(-1))

ans = 0

for i in range(N):
    for j in range(K+1):
        if dp1[j] and dp2[N-1-i][K-j]:
            break
    else:
        ans += 1
    
    for j in range(K, -1, -1):
        if dp1[j] and j+A[i]<=K:
            dp1[j+A[i]] = True

print(ans)