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