#include <bits/stdc++.h>
using namespace std;
double F[2222][2222];
double p;
double f(int n, int t) {
  if (t == 0 || n == 0) return 0;
  double &res = F[n][t];
  if (res < -1) {
    res = p * f(n - 1, t - 1) + p + (1 - p) * f(n, t - 1);
  }
  return res;
}
int main() {
  int n, t;
  for (; cin >> n >> p >> t;) {
    memset(F, -2, sizeof F);
    printf("%.8lf\n", f(n, t));
  }
  return 0;
}
