2021 THTB DANANG B1. Số giàu có

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

const int bmax=1000005;

ll p[bmax];
int i,j,a,d,b,t;

void sang(int n)
{
    for(int i=1;i<=n;i++)
        p[i]=1;
    for(int i=2;i<=n/2;i++)
    {
        j=i*2;
        while(j<=n)
        {
            p[j]=p[j]+i;
            j=j+i;
        }
    }
}

int main()
{
    freopen("giauco.inp","r",stdin);
    freopen("giauco.out","w",stdout);
    int n;
    cin>>n;
    sang(n);
   // cout<<(p[24]+24)<<endl;
    ll ma=0,ima;
    for(int i=1;i<=n;i++)
    {
        if(p[i]+i>ma)
        {
            ima=i;
            ma=p[i]+i;
        }
    }
    cout<<ima;

}