#include <bits/stdc++.h>
const long double PI = 3.14159265358979311600;
using namespace std;
double d[2010][2010];
int main() {
  long long n, t, i, j;
  double p, mt = 0, sf;
  cin >> n >> p >> t;
  for (i = 0; i < 2010; i++)
    for (j = 0; j < 2010; j++) d[i][j] = 0;
  d[0][0] = 1.0;
  for (i = 1; i <= t; i++) {
    sf = 0.0;
    for (j = 0; j < min(n, t); j++) {
      d[i][j] = d[i - 1][j] * (1.0 - p);
      if (j - 1 >= 0) d[i][j] += d[i - 1][j - 1] * p;
      sf += d[i][j];
    }
    d[i][min(n, t)] = 1.0 - sf;
  }
  for (i = 0; i <= n; i++) mt += d[t][i] * double(i);
  printf("%.20lf\n", mt);
  return 0;
}
