N, x = map(int, input())
child_list = list(map(int, input()))

nokori = x - min(child_list)
please_child = 0 
while nokori >=0:
    please_child +=1
    mini = min(child_list)
    child_list.remove(mini)
    if child_list == []:
        break
    nokori -= min(child_list)
print(please_child)