#include <bits/stdc++.h>
using namespace std;
double dp[2222][2222];
int N, T;
double P;
int main() {
  cin >> N >> P >> T;
  int i, j, k;
  dp[0][0] = 1;
  for (i = 0; i <= T; i++) {
    for (j = 0; j <= i; j++) {
      if (j >= N) {
        dp[i + 1][j] += dp[i][j];
        continue;
      }
      dp[i + 1][j + 1] += dp[i][j] * P;
      dp[i + 1][j] += dp[i][j] * (1 - P);
    }
  }
  double ans = 0;
  for (i = 1; i <= N; i++) {
    ans += dp[T][i] * double(i);
  }
  printf("%f\n", ans);
  return 0;
}
