#include <bits/stdc++.h>
using namespace std;
long double pow(long double k, long long int l) {
  if (l == 0) {
    return 1;
  }
  long double ans = k;
  int i;
  for (i = 2; i <= l; i++) {
    ans = ans * k;
  }
  return ans;
}
long double z[2001][2001];
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long int i, j, k, l, m, n, o, q, r, w, c = 0, t, cnt, x, y;
  long double p, ans = 0, sum;
  cin >> n >> p >> t;
  for (i = 0; i <= n; i++) {
    z[i][0] = 0.00;
  }
  for (j = 0; j <= t; j++) {
    z[0][j] = 0.00;
  }
  z[0][1] = (1 - p);
  z[1][1] = (p);
  for (j = 0; j < t; j++) {
    for (i = 0; i <= j + 1; i++) {
      if (i < n) {
        z[i + 1][j + 1] += z[i][j] * p;
        z[i][j + 1] += z[i][j] * (1 - p);
      } else {
        z[i][j + 1] += z[i][j];
      }
    }
  }
  for (i = 1; i <= n; i++) {
    ans += z[i][t] * i;
  }
  cout << std::fixed << ans << endl;
}
