#include <bits/stdc++.h>
using namespace std;
int main() {
  int a[6];
  double sum = 0;
  for (int i = 0; i < 6; i++) cin >> a[i], sum += a[i];
  for (int i = 0; i < 6; i++)
    for (int j = i + 1; j < 6; j++)
      for (int k = j + 1; k < 6; k++)
        if (a[i] + a[j] + a[k] == (sum / 2)) return cout << "YES" << endl, 0;
  return cout << "NO" << endl, 0;
}
