#include <bits/stdc++.h>
using namespace std;
double dp[2005][2];
int main() {
  int n, t;
  double p;
  scanf("%d%lf%d", &n, &p, &t);
  dp[0][0] = 1;
  int m = 0;
  for (int i = 0; i < t; i++) {
    for (int j = 0; j <= n; j++) {
      if (j == 0)
        dp[j][1 ^ m] = dp[j][m] * (1.0 - p);
      else if (j == n)
        dp[j][1 ^ m] = dp[j][m] + dp[j - 1][m] * p;
      else
        dp[j][1 ^ m] = dp[j][m] * (1.0 - p) + dp[j - 1][m] * p;
    }
    m ^= 1;
  }
  double ans = 0;
  for (int i = 0; i <= n; i++) {
    ans += dp[i][m] * i;
  }
  printf("%f\n", ans);
  return 0;
}
