#include <bits/stdc++.h>
using namespace std;
int n, t;
double p;
double f[2005][2005];
int main() {
  scanf("%d%lf%d", &n, &p, &t);
  f[0][0] = 1;
  for (register int i = 1; i <= t; i++)
    for (register int j = 0; j <= n; j++)
      if (j == n)
        f[i][j] = f[i - 1][j - 1] * p + f[i - 1][j];
      else if (j == 0)
        f[i][j] = f[i - 1][j] * (1 - p);
      else
        f[i][j] = f[i - 1][j - 1] * p + f[i - 1][j] * (1 - p);
  register double ans = 0;
  for (register int i = 0; i <= n; i++) ans += i * f[t][i];
  printf("%.12lf", ans);
  return 0;
}
