#include <bits/stdc++.h>
using namespace std;
string sss = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
long long n, t, i, j;
double p, dp[2009];
void solve(long long CS) {
  cin >> n >> p >> t;
  dp[0] = 1;
  while (t--) {
    for (i = n - 1; i >= 0; i--) {
      dp[i + 1] += (dp[i] * p);
      dp[i] *= (1.0 - p);
    }
  }
  double res = 0;
  for (i = 1; i <= n; i++) res += (dp[i] * i);
  printf("%.9lf\n", res);
}
int main() {
  long long t, no = 0;
  t = 1;
  while (t--) solve(++no);
}
