#include <bits/stdc++.h>
using namespace std;
double f[2020][2020], ans, p;
int n, t;
int main() {
  cin >> n >> p >> t;
  f[0][0] = 1;
  for (int i = 1; i <= t; ++i)
    for (int j = 0; j <= n; ++j) {
      if (j == 0)
        f[i][j] = f[i - 1][j] * (1 - p);
      else if (j == n)
        f[i][j] = f[i - 1][j] + f[i - 1][j - 1] * p;
      else
        f[i][j] = f[i - 1][j - 1] * p + f[i - 1][j] * (1 - p);
    }
  for (int i = 1; i <= n; ++i) ans += f[t][i] * i;
  printf("%.12lf", ans);
  return 0;
}
