#include<iostream>
using namespace std;
int main() {
    int n;
    setlocale(LC_ALL, "Rus");
    cin >> n;
    int i = n / 2;
    while (n%i != 0) i--;
    if (i != 1) cout << "наиб. делитель " << i << endl;
    else cout << "число простое n";
    system("pause");
    return 0;
}

for (int i = n; i > 0; i--) {
   if n%i==0 break;//here value i that you find
}