#include <bits/stdc++.h>
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int dx[8] = {1, -1, 0, 0, -1, -1, 1, 1};
int dy[8] = {0, 0, -1, 1, -1, 1, -1, 1};
vector<int> adj[300010], val(300010, 1), vis(300010, 0), dis1(300010, 0),
    dis2(300010, 0);
int myrandom(int i) { return std::rand() % i; }
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long n, t;
  long double p;
  cin >> n >> p >> t;
  long double dp[t + 2][n + 2];
  memset(dp, 0, sizeof(dp));
  dp[0][0] = 1;
  for (int i = 0; i <= t; i++) {
    for (int j = 0; j <= n; j++) {
      if (j < n) {
        dp[i + 1][j + 1] += dp[i][j] * p;
        dp[i + 1][j] += dp[i][j] * (1 - p);
      } else {
        dp[i + 1][j] += dp[i][j];
      }
    }
  }
  long double ans = 0;
  for (int i = 1; i <= n; i++) {
    ans = ans + i * (dp[t][i]);
  }
  cout << fixed << setprecision(20) << ans << '\n';
}
