#include <iostream>

typedef long long ll;

int main(){
    ll N, _N;
    scanf("%lld", &N);
    _N = N;
    
    ll res = 1ll;
    
    for(ll i=2;i*i<=N;i++){
        ll productSum = 1ll, product = 1ll;
        while(N % i == 0){
            product *= i;
            productSum += product;
            N /= i;
        }

        res *= productSum;
    }

    if(N > 1){res *= 1 + N;}
    
    if(_N % 2 == 0){
        res -= _N;
    }

    printf("%lld\n", res);
}