#約数全部
def Divisors(N):
    N=abs(N)
    L,U=[],[]
    k=1
    while k*k <=N:
        if N%k== 0:
            L.append(k)
            if k*k!=N:
                U.append(N//k)
        k+=1
    return L+U[::-1]

def check(N,r):
    p=N%r
    while N:
        if N%r!=p:
            return False
        N//=r
    return True
#================================================
N=int(input())
D=Divisors(N)

X=N+1
for a in D:
    M=N//a
    B=Divisors(M-1)

    for p in B:
        if p>=X:
            break

        if 2<=p and check(N,p):
            X=min(X,p)
print(X)