#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int a = 1;
  int s = n - 1;
  for (int i = 1; i < n - 1; i++) {
    if (i % 3 != 0 && (s - i) % 3 != 0) {
      cout << a << " " << i << " " << s - i;
      break;
    }
  }
  return 0;
}
