#include <bits/stdc++.h>
const int MAXN = 2007;
double dp[MAXN][MAXN];
int main() {
  int n, t;
  double p;
  scanf("%d%lf%d", &n, &p, &t);
  dp[0][0] = 1;
  for (int i = 0; i < t; ++i) {
    dp[i + 1][n] += dp[i][n];
    for (int j = 0; j < n; ++j) {
      dp[i + 1][j + 1] += dp[i][j] * p;
      dp[i + 1][j] += dp[i][j] * (1 - p);
    }
  }
  double ans = 0;
  for (int i = 0; i <= n; ++i) {
    ans += dp[t][i] * i;
  }
  printf("%.6f", ans);
  return 0;
}
