#include <bits/stdc++.h>
using namespace std;
double dp[2002][2];
double p, q;
int main() {
  int n, t;
  cin >> n >> p >> t;
  q = 1.0000 - p;
  for (int i = 0; i <= n; i++) dp[i][0] = 0;
  for (int i = 0; i <= 2; i++) dp[0][i] = 0;
  for (int i = 1; i <= t; i++) {
    for (int j = 1; j <= n; j++)
      dp[j][i % 2] =
          p * (dp[j - 1][(i - 1) % 2] + 1.0000000) + q * dp[j][(i - 1) % 2];
  }
  printf("%.8f\n", dp[n][t % 2]);
  return 0;
}
