N=int(input())
for i in range(2,int(N**0.5)+1):
  M=N
  P=[]
  while M:
    P.append(M%i)
    M//=i
  if len(set(P))==1:
    print(i)
    exit()
if N<=10**6:
  for i in range(2,N+3):
    M=N
    P=[]
    while M:
      P.append(M%i)
      M//=i
    if len(set(P))==1:
      print(i)
      exit()
P=N
for i in range(1,int(N**0.5)+1):
  if N%i==0 and i*(i+1)<N:
    P=min(P,(N//i)-1)
if P==1:
  P=N+1
print(P)