def revFact(n):
if(n<1):
return False
k=1
while(n>1):
k+=1
if(n%k)!=0:
return False
n=n//k
return k
revFact(1000)
ZGVmIHJldkZhY3Qobik6CiAgICBpZihuPDEpOgogICAgICAgIHJldHVybiBGYWxzZQogICAgaz0xCiAgICB3aGlsZShuPjEpOgogICAgICAgIGsrPTEKICAgICAgICBpZihuJWspIT0wOgogICAgICAgICAgICByZXR1cm4gIEZhbHNlCiAgICAgICAgbj1uLy9rCiAgICByZXR1cm4gawpyZXZGYWN0KDEwMDAp