#include <bits/stdc++.h>
using namespace std;
double dp[3000][3000];
int main() {
  double p, sum;
  long long n, t, i, j;
  cin >> n >> p >> t;
  dp[1][1] = p;
  dp[1][0] = (1 - p);
  for (i = 1; i <= t; i++) {
    for (j = 0; j <= min(n, t); j++) {
      if (j == n) {
        dp[i + 1][j] = dp[i + 1][j] + dp[i][j];
      } else {
        dp[i + 1][j] = dp[i + 1][j] + dp[i][j] * (1 - p);
        dp[i + 1][j + 1] = dp[i + 1][j + 1] + dp[i][j] * (p);
      }
    }
  }
  sum = (double)(0);
  for (i = 0; i <= min(n, t); i++) {
    sum += (i * dp[t][i]);
  }
  cout << setprecision(7) << sum;
  return 0;
}
