Diary_3.11

#define int long long
void solve(){
    int n;  cin >> n;
    int ans = 0;
    for(int i=1; i<=n; i++){
        int l = i;
        int r = n/(n/i);
        int len = r-l+1;
        ans += len*(n/i);
        i = r;
    }
    cout << ans << endl;
}