#include <bits/stdc++.h>
using namespace std;
int n, m;
double w;
int gcd(int a, int b) {
  if (b) return gcd(b, a % b);
  return a;
}
int main() {
  cin >> n >> w >> m;
  int d = gcd(n, m), N = n / d, M = m / d;
  if (N + 1 < M) {
    cout << "NO";
    return 0;
  }
  cout << "YES" << endl << setprecision(11);
  for (int i = 0; i < d; i++) {
    if (M <= N) {
      int s = M * N, cur = 1, cup = 0;
      vector<pair<int, int> > v;
      for (int j = 0; j < N; j++) {
        cup += M;
        if (cup < N) cout << j + 1 + i * N << " " << w << " ";
        if (cup >= N) {
          cout << j + 1 + i * N << " " << w * (N - cup + M) / M << endl;
          cur++, cup -= N;
          if (cup) cout << j + 1 + i * N << " " << w * cup / M << " ";
        }
      }
    } else {
      for (int j = 0; j < N; j++)
        cout << j + 1 + i * N << " " << w * N / M << endl;
      for (int j = 0; j < N; j++) cout << j + 1 + i * N << " " << w / M << " ";
      cout << endl;
    }
  }
}
