#include <bits/stdc++.h>
using namespace std;
const double eps = 1e-8;
const double pi = acos(-1.0);
const int INF = 0x3f3f3f3f;
const int mod = 1e9 + 7;
long long powmod(long long a, long long b) {
  long long res = 1;
  a %= mod;
  assert(b >= 0);
  for (; b; b >>= 1) {
    if (b & 1) res = res * a % mod;
    a = a * a % mod;
  }
  return res;
}
double dp[2010][2010];
int main() {
  int n, t;
  double p;
  cin >> n >> p >> t;
  dp[0][0] = 1;
  for (int i = 1; i <= t; i++) {
    dp[i][0] = dp[i - 1][0] * (1 - p);
    for (int j = 1; j < n; j++)
      dp[i][j] = dp[i - 1][j] * (1 - p) + dp[i - 1][j - 1] * p;
    dp[i][n] = dp[i - 1][n] + dp[i - 1][n - 1] * p;
  }
  double ans = 0;
  for (int i = 0; i <= n; i++) {
    ans += dp[t][i] * i;
  }
  printf("%.8f\n", ans);
  return 0;
}
