#include <bits/stdc++.h>
using namespace std;
inline void inputfile() {}
inline void cpp_input() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
}
double dp[2003][2003] = {0};
double func(int n, double p, int t) {
  dp[1][0] = 1 - p;
  dp[1][1] = p;
  for (int(i) = (2); (i) < (t + 1); ++(i)) dp[i][0] = (1 - p) * dp[i - 1][0];
  for (int(i) = (1); (i) < (t + 1); ++(i)) {
    for (int(j) = (1); (j) < (n + 1); ++(j)) {
      if (j == 1 && i == 1) continue;
      dp[i][j] = dp[i - 1][j - 1] * p;
      if (j == n)
        dp[i][j] = dp[i][j] + dp[i - 1][j];
      else
        dp[i][j] += (1 - p) * dp[i - 1][j];
    }
  }
  double ans = 0.0;
  for (int(i) = (0); (i) < (n + 1); ++(i)) {
    ans += i * dp[t][i];
  }
  return ans;
}
int main(int argc, char const *argv[]) {
  inputfile();
  double p;
  int n, t;
  scanf("%d", &n);
  scanf("%lf", &p);
  scanf("%d", &t);
  double ans = func(n, p, t);
  printf("%.8f\n", ans);
  return 0;
}
