#include <stdio.h>
#include <stdlib.h>

double f(double x) { return x * x; }

int g(int s, int n) {
  return (n == 0) ? s
                  : (f((double)rand() / RAND_MAX) > (double)rand() / RAND_MAX) ? g(s + 1, n - 1)
                                                                               : g(s, n - 1);
}

#define SEED 31415926
#define N 10000
int main() {
  srand(SEED);
  printf("%f\n", (double)g(0, N) / N);
  return 0;
}
/* end */