#include <bits/stdc++.h>
using namespace std;
int n, t;
double p, np, f[2020][2020];
int main() {
  scanf("%d%lf%d", &n, &p, &t);
  np = 1 - p;
  f[0][0] = 1;
  for (int i = 1; i <= t; i++) f[i][0] = f[i - 1][0] * np;
  for (int i = 1; i <= t; i++)
    for (int j = 1; j < n; j++)
      f[i][j] = f[i - 1][j - 1] * p + f[i - 1][j] * np;
  for (int i = 1; i <= t; i++) f[i][n] = f[i - 1][n - 1] * p + f[i - 1][n];
  double ans = 0;
  for (int i = 0; i <= n; i++) ans += f[t][i] * i;
  printf("%.7lf\n", ans);
  return 0;
}
