频繁RE不同测试点，求调

#include <bits/stdc++.h>
using namespace std;
#define int long long
const int N = 1e6+10;
int a[N];
signed main()
{
    int n;
    scanf("%d",&n);
    int m = n;
    int ans = 0;
    for(int i = 1;i<=n;i++)
    {
        a[i]=(n/i)*(m/i);
    }
    for(int i = n;i;i--)
    {
        for(int j = 2;j<=n/i;j++)
        {
            a[i]-=a[i*j];
        }
        ans+=a[i]*i;
    }
    cout<<ans<<"\n";
    return 0;
}