#include <stdio.h>

#include <math.h>

int fun0(int x) {

x=2*x;

return x;

}

int main(int argc, const char * argv[]) {

int i;

i =1;

while ( i > 0) {

i=fun0(i);

}

float f = i;

if(i<0) printf(" precision is %f bits \n",log(-f)/log(2.)+1);

return 0;

}