太裤啦

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
typedef long long ll;
ll get_oula(int x)
{
    ll ans = x;
    for(int i = 2;i <= x / i;i++)
    {
        if(x % i == 0) ans = 1ll * ans / i * (i - 1);
        while(x % i == 0) x /= i;
    }
    if(x > 1) ans = ans / x * (x - 1);
    return ans;
}
int main()
{
    int n;scanf("%d",&n);
    ll ans = 0;
    for(int d = 1;d <= n / d;d++)
    {
        if(n % d == 0)
        {
            ans += 1ll * (n / d) * get_oula(d);
            int c = n / d;
            if(d != c) ans += 1ll * d * get_oula(c);
        }
    }
    cout << ans << endl;
    return 0;
}