#include <bits/stdc++.h>   using namespace std;   int n, w, m;   double a[100];   int kol[100];   vector<pair<int, double> > v[100];   int main() {     cin >> n >> w >> m;     double q = n * w * 1.0 / m;     memset(kol, 0, sizeof(kol));     for (int i = 0; i < 100; ++i) a[i] = w;     for (int i = 0; i < m; ++i) {       double p = q;       int z = 0;       for (int j = 0; j < n; ++j) {         if (a[j] > 1e-9) {           double temp = min(p, a[j]);           v[i].push_back(make_pair(j + 1, temp));           p -= temp;           a[j] -= temp;           ++z;           ++kol[j];           if (kol[j] > 2) {             cout <<  NO n ;             return 0;           }           if (p < 1e-9) break;         }       }       if (z == 0 || p > 1e-9) {         cout <<  NO n ;         return 0;       }     }     cout <<  YES n ;     for (int i = 0; i < m; ++i) {       for (int j = 0; j < v[i].size(); ++j) {         if (j) cout <<    ;         cout << v[i][j].first <<     << fixed << setprecision(10)              << v[i][j].second;       }       cout << endl;     }     return 0;   }   