#include <bits/stdc++.h>
using namespace std;
template <typename S, typename T>
ostream& operator<<(ostream& out, pair<S, T> const& p) {
  out << '(' << p.first << ", " << p.second << ')';
  return out;
}
template <typename T>
ostream& operator<<(ostream& out, vector<T> const& v) {
  long long l = v.size();
  for (long long i = 0; i < l - 1; i++) out << v[i] << ' ';
  if (l > 0) out << v[l - 1];
  return out;
}
template <typename T>
void trace(const char* name, T&& arg1) {
  cout << name << " : " << arg1 << "\n";
}
template <typename T, typename... Args>
void trace(const char* names, T&& arg1, Args&&... args) {
  const char* comma = strchr(names + 1, ',');
  cout.write(names, comma - names) << " : " << arg1 << " | ";
  trace(comma + 1, args...);
}
long double eps = 1e-9;
long long n, w, m;
void solve() {
  cin >> n >> w >> m;
  string ans = "";
  long double one = 1.0;
  long double each = (w * one * n * one) / (m * one);
  long long curr = 0;
  long long bottle = 1;
  long double cap = w;
  long long t = 1;
  set<long long> arr[n + 2];
  while (curr < m) {
    long double tofill = each;
    while (tofill > eps) {
      if (cap >= tofill) {
        ans += to_string(bottle);
        ans += " ";
        ans += to_string(tofill);
        ans += " ";
        cap -= tofill;
        arr[bottle].insert(curr);
        if (arr[bottle].size() > 2) {
          cout << "NO\n";
          return;
        }
        tofill = 0;
      } else {
        if (cap > eps) {
          tofill -= cap;
          ans += to_string(bottle);
          ans += " ";
          ans += to_string(cap);
          ans += " ";
          arr[bottle].insert(curr);
          if (arr[bottle].size() > 2) {
            cout << "NO\n";
            return;
          }
        }
        bottle++;
        cap = w;
        t = 1;
      }
    }
    ans += "\n";
    curr++;
  }
  cout << "YES\n";
  cout << ans;
}
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long t;
  t = 1;
  while (t--) solve();
}
