#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n;
  cin >> n;
  long long a, b, c;
  if (n % 3 == 0) {
    a = n - 2;
    b = 1;
    c = 1;
  } else {
    if ((n + 1) % 3 == 0) {
      a = n - 3;
      b = 2;
      c = 1;
    } else if ((n - 1) % 3 == 0) {
      a = n - 2;
      b = 1;
      c = 1;
    }
  }
  cout << a << " " << b << " " << c;
  return 0;
}
