#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair< int, int > pii;
typedef vector< int > vi;
typedef vector< vi > vvi;
typedef vector< ll > vl;
typedef vector< vl > vvl;
typedef vector< pii > vp;
typedef vector< vp > vvp;
typedef vector< string > vs;
typedef vector< double > vd;
typedef vector< vd > vvd;

template< class T1, class T2 >
int upmin( T1 &x, T2 v ){
  if( x > v ){
    x = v;
    return 1;
  }
  return 0;
}

template< class T1, class T2 >
int upmax( T1 &x, T2 v ){
  if( x < v ){
    x = v;
    return 1;
  }
  return 0;
}

ll N;

void init(){
  cin >> N;
}

void preprocess(){
  
}

void solve(){
  ll a = N + 1;
  ll b = N;
  if( a % 2 )
    b /= 2;
  else
    a /= 2;
  ll x = __gcd( N, a ) / __gcd( a, b ) * __gcd( N, b );
  ll ans = 0;
  for( int i = 1; 1LL * i * i <= x; ++i ) if( x % i == 0 ){
    ans += i;
    if( 1LL * i * i != x )
      ans += x / i; 
  }
  cout << ans << endl;
}

signed main(){
  ios::sync_with_stdio( 0 );
  init();
  preprocess();
  solve();
  return 0;
}