#include <stdio.h>
#include <stdlib.h>
int main(){
  int n = 1<<27, q=0;
  double f=1./n, w11 = 0, w12 = 0.;
  while(n--) {double x = random() * 0x1p-31, y = random() * 0x1p-31;
     if(x+y<1.) {w12 += x*y; w11 += x*x;} else ++q;}
  printf("w11=%12.7f, w12=%12.7f, out=%x\n", w11 * f, w12 * f, q);
  return 0;}

// indeed: w11=   0.0833299, w12=   0.0416702, out=3fff6a1