#include <bits/stdc++.h>
using LL = long long;
const int N = 2000 + 5;
const double eps = 1e-8;
int n, t;
double p;
double dp[N][N];
inline int dcmp(double x) { return (x > eps) - (x < -eps); }
double solve() {
  if (dcmp(p) == 0) {
    return 0;
  }
  if (dcmp(p - 1) == 0) {
    return std::min(t, n);
  }
  dp[0][0] = 1.;
  double ret = 0;
  for (int i = 0; i < t; ++i) {
    for (int j = 0; j < n; ++j) {
      dp[i + 1][j] += dp[i][j] * (1 - p);
      dp[i + 1][j + 1] += dp[i][j] * p;
    }
  }
  for (int i = 0; i <= t; ++i) {
    ret += dp[i][n] * n;
  }
  for (int i = 0; i < n; ++i) {
    ret += dp[t][i] * i;
  }
  return ret;
}
int main() {
  scanf("%d%lf%d", &n, &p, &t);
  printf("%.13f\n", solve());
  return 0;
}
