#include <bits/stdc++.h>
#pragma comment(linker, "/STACK:256000000")
using namespace std;
const double PI = acos(-1.0);
const int INF = 1e9;
const int MOD = 1e9 + 7;
const double RRR = 180.0 / PI;
const long double EPS = 1e-8;
long long fact(long long n) {
  long long ans = 1;
  for (int i = 2; i <= n; i++) {
    ans *= i;
  }
  return ans;
}
int main() {
  double TIME_START = clock();
  vector<vector<long double> > P(2005, vector<long double>(2005, 0.0));
  int n, t;
  double p;
  cin >> n >> p >> t;
  P[0][0] = 1.0;
  for (int i = 1; i <= t; i++) {
    P[i][0] = P[i - 1][0] * (1.0 - p);
    for (int j = 1; j <= n; j++) {
      if (j != n) {
        P[i][j] = P[i - 1][j] * (1.0 - p) + p * P[i - 1][j - 1];
      } else {
        P[i][j] = P[i - 1][j] + p * P[i - 1][j - 1];
      }
    }
  }
  long double ans = 0.0;
  for (int i = 0; i <= n; i++) {
    ans += P[t][i] * i;
  }
  printf("%.10f", (double)ans);
  return 0;
}
