C

k = [[int(i), 1] for i in input().split()]
k.sort()
p = list(map(int, input().split()))
res = 0

for i in p:
    for j in range(len(k)):
        if(k[j][1] and i <= k[j][0]):
            k[j][1] = 0
            res += 1
            break
print(res)