#include <bits/stdc++.h>
using namespace std;
double memo[2002][2002];
double p;
double get(int n, int t) {
  if (n == 0 and t == 0) return 1.0;
  if (n < 1) return 0;
  if (t < 1) return 0;
  if (n > t) return 0;
  double &ret = memo[n][t];
  if (ret == ret) return ret;
  ret = get(n - 1, t - 1) * p + get(n, t - 1) * (1 - p);
  return ret;
}
int main() {
  int n, t;
  cin >> n >> p >> t;
  double ans = 0;
  memset(memo, -1, sizeof memo);
  get(n, t);
  for (int i = 1; i <= n; i++)
    for (int j = 1; j <= t; j++) ans += get(i, j);
  printf("%lf", ans);
  return 0;
}
