#include <bits/stdc++.h>
using namespace std;
double dp[2005][2005], p;
int main() {
  int n, t;
  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] + 1) * p + dp[i - 1][j] * (1 - p);
  printf("%.10lf", dp[t][n]);
}
