#include <bits/stdc++.h>
using namespace std;
int sol() {
  int n, w, m;
  cin >> n >> w >> m;
  for (int i = 2; i <= m; ++i) {
    int now = (i - 1) * w * (m - n);
    if (now == n * w) break;
    if (now > n * w) {
      cout << "NO" << endl;
      return 0;
    }
  }
  cout << "YES" << endl;
  int last = w * m, v = w * n, milk = 1;
  for (int i = 1; i <= m; ++i) {
    if (last == v) {
      printf("%d %.9lf\n", milk, (double)v / m);
      milk++;
      last = w * m;
      continue;
    }
    if (last > v) {
      printf("%d %.9lf\n", milk, (double)v / m);
      last -= v;
      continue;
    }
    printf("%d %.9lf ", milk, (double)last / m);
    int curV = v - last;
    while (curV > w * m) {
      milk++;
      curV -= w * m;
      printf("%d %.9lf ", milk, (double)w);
    }
    milk++;
    if (curV == w * m) {
      printf("%d %.9lf\n", milk, (double)w);
      milk++;
      last = w * m;
    } else {
      printf("%d %.9lf\n", milk, (double)curV / m);
      last = w * m - curV;
    }
  }
  return 0;
}
int main() {
  sol();
  return 0;
}
