#include <bits/stdc++.h>
using namespace std;
int n, t, i, j;
double p, ans, f[2005][2005];
int main() {
  cin >> n >> p >> t;
  f[0][0] = 1;
  for (int i = 1; i <= t; i++) {
    f[i][0] = f[i - 1][0] * (1 - p);
  }
  for (i = 1; i <= t; i++)
    for (j = 1; j <= n; j++) {
      if (j < n) f[i][j] = f[i][j] + f[i - 1][j] * (1 - p);
      f[i][j] = f[i][j] + f[i - 1][j - 1] * p;
    }
  for (i = 1; i <= n; i++) ans = ans + i * f[t][i];
  for (i = 0; i < t; i++) ans = ans + n * f[i][n];
  printf("%0.10lf", ans);
}
