#include <bits/stdc++.h>
double f[2010][2010], p;
int n, t;
int main() {
  scanf("%d%lf%d", &n, &p, &t);
  for (int i = 1; i <= t; ++i)
    for (int j = 1; j <= n; ++j)
      f[i][j] = p * (f[i - 1][j - 1] + 1) + (1 - p) * f[i - 1][j];
  printf("%.7f", f[t][n]);
  return 0;
}
