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]


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]*(K+1) for _ in range(N+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]*(K+1) for _ in range(N+1)]
dpr[0][0] = 1
#配るDP
for i in range(N):
    a = A[i]
    for j in range(K+1):
        if dpl[i][j] == 0: continue
        #使わない
        dpl[i+1][j] |= dpl[i][j]
        #使う
        if j+a <= K:
            dpl[i+1][j+a] |= dpl[i][j]
    a = A[N-1-i]
    for j in range(K+1):
        if dpr[i][j] == 0: continue
        #使わない
        dpr[i+1][j] |= dpr[i][j]
        #使う
        if j+a <= K:
            dpr[i+1][j+a] |= dpr[i][j]
if dpl[N][K] == 0:
    print(-1);exit()
#print(dpl)
#print(dpr)
ans = 0
for i in range(N):
    for x in range(K+1):
        if dpl[i][x] == 1 and dpr[N-1-i][K-x] == 1:
            break
    else:
        ans += 1
print(ans)