题解 | 小红的合数寻找

def f(n):
    k=0
    if n==1 or n==2:
        return 0
    else:
        for i in range(2,n):
            if n%i==0:
                k=i
    if k==0:
        return 0
    else:
        return n
           
x=int(input())
x1=0
for j in range(x,2*x+1):
    if f(j)!=0:
        x1=j
if x1==0:
    print(-1)
else:
    print(x1)