#include <bits/stdc++.h>
using namespace std;
int n, t, k;
double dp[2020][2];
double p;
int main() {
  scanf("%d%lf%d", &n, &p, &t);
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= t; j++) {
      dp[j][k] = dp[j - 1][k] * (1 - p) + (dp[j - 1][!k] + 1) * p;
    }
    k = !k;
  }
  printf("%lf", dp[t][!k]);
  return 0;
}
