#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <functional>
#include <iostream>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

using Int = long long;

template <class T1, class T2> ostream &operator<<(ostream &os, const pair<T1, T2> &a) { return os << "(" << a.first << ", " << a.second << ")"; };
template <class T> ostream &operator<<(ostream &os, const vector<T> &as) { const int sz = as.size(); os << "["; for (int i = 0; i < sz; ++i) { if (i >= 256) { os << ", ..."; break; } if (i > 0) { os << ", "; } os << as[i]; } return os << "]"; }
template <class T> void pv(T a, T b) { for (T i = a; i != b; ++i) cerr << *i << " "; cerr << endl; }
template <class T> bool chmin(T &t, const T &f) { if (t > f) { t = f; return true; } return false; }
template <class T> bool chmax(T &t, const T &f) { if (t < f) { t = f; return true; } return false; }
#define COLOR(s) ("\x1b[" s "m")


using Double = double;
constexpr Double INF = 1e+100;

/*
  reset at u ==> keep resetting at 0,...,u
  wait for n consecutive success:
    \sum[1<=i<=n] (1/(1-P))^i = ((1/(1-P))^N - 1) / P
*/

int N, K;
Double P;

int main() {
  for (; ~scanf("%d%d%lf", &N, &K, &P); ) {
    chmin(K, 1000);
    
    vector<Double> cs(N + 1);
    cs[0] = 1;
    for (int n = 1; n <= N; ++n) cs[n] = cs[n - 1] / (1-P);
    for (int n = 0; n <= N; ++n) cs[n] = (cs[n] - 1) / P;
    
    vector<Double> dp(N + 1, INF);
    dp[N] = 0;
    for (int k = 0; k <= K; ++k) {
      for (int u = N; --u >= 0; ) {
        dp[u] = 1 + (1-P) * dp[u + 1] + P * min(dp[u], cs[u + 1] + dp[u + 1]);
      }
// if(N<=10)cerr<<k<<": "<<dp<<endl;
    }
    printf("%.15f\n", dp[0]);
  }
  return 0;
}