#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#define NUM 10000
#define EXA 1000
int main()
{
  float count,count2=0.00;
  float x,y;
  srand((unsigned) time(NULL));
  for(count=0;count<NUM;count++){
    x=(rand()%EXA)/(double)EXA;
    y=(rand()%EXA)/(double)EXA;
    if(x*x+y*y<1.00)
      count2=count2+1;
  }
  printf("%f\n",4.0*(count2/NUM));
}