#include <bits/stdc++.h>
using namespace std;
double dp[2001][2001] = {0};
int main() {
  int n, t;
  double p;
  scanf("%d%lf%d", &n, &p, &t);
  float ans = 0;
  dp[1][1] = p;
  float tmp = 1;
  for (int i = 1; i <= t; i++) {
    tmp *= (1 - p);
    dp[i][0] = tmp;
  }
  for (int i = 2; i <= t; i++) {
    for (int j = 1; j <= min(i, n); j++) {
      if (j == n)
        dp[i][j] += dp[i - 1][j];
      else
        dp[i][j] += dp[i - 1][j] * (1 - p);
      dp[i][j] += dp[i - 1][j - 1] * p;
    }
  }
  for (int i = 1; i <= min(n, t); i++) {
    ans += i * dp[t][i];
  }
  printf("%lf\n", ans);
}
