#include <bits/stdc++.h>
using namespace std;
int main() {
  long long a, s, d, i, j, k;
  long double tt;
  cin >> a >> tt >> s;
  vector<vector<long double> > dp(3000, vector<long double>(3000, 0.0));
  dp[0][0] = 1;
  for (i = 0; i <= s; i++) {
    for (j = 0; j <= a; j++) {
      if (j != a) {
        dp[i + 1][j] += dp[i][j] * (1.0 - tt);
        dp[i + 1][j + 1] += dp[i][j] * 1.0 * (tt);
      } else
        dp[i + 1][j] += dp[i][j];
    }
  }
  long double sum = 0.0;
  for (i = 0; i <= a; i++) sum += dp[s][i] * i;
  cout << fixed << setprecision(10);
  cout << sum;
}
