#include <bits/stdc++.h>
using namespace std;
int n, T;
double p, dp[2010][2010];
double call(int i, int t) {
  if (i == n) return n;
  if (t == T) return i;
  if (dp[i][t] != -1) return dp[i][t];
  double a, b;
  a = p * call(i + 1, t + 1);
  b = (1 - p) * call(i, t + 1);
  return dp[i][t] = a + b;
}
int main() {
  int i, j;
  scanf("%d%lf%d", &n, &p, &T);
  for (i = 0; i <= n; i++)
    for (j = 0; j <= T; j++) dp[i][j] = -1;
  printf("%.10lf\n", call(0, 0));
  return 0;
}
