#include <cstdio>
#include <vector>
using namespace std;
int main()
{
  int n,max = -1234567;
  scanf("%d",&n);
  vector<int> a;
  for (int j = 1;j <= n;j++)
  {
    if (n % j == 0 and j < n)
    {
      a.push_back(j);
        
    }
  }
  
  for (int i = 0;i < a.size();i++)
  {
    if (a[i] > max)
    {
      max = a[i];
    }
  }
  printf("%d",max);
}