#include <bits/stdc++.h>
using namespace std;
int n, t;
double dp[2020][2020];
double p;
int main() {
  scanf("%d%lf%d", &n, &p, &t);
  for (int i = 1; i <= t; i++) {
    for (int j = 1; j <= n; j++) {
      dp[i][j] = dp[i - 1][j] * (1 - p) + (dp[i - 1][j - 1] + 1) * p;
    }
  }
  printf("%lf", dp[t][n]);
  return 0;
}
