// verifast_options{disable_overflow_check target:ILP32}

extern void abort(void);//@ requires true; 
//@ ensures true;

extern void __assert_fail(const char *, const char *, unsigned int, const char *) __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__noreturn__));
void reach_error() //@ requires false; 
//@ ensures true;
{ __assert_fail("0", "n.c11.c", 3, "reach_error"); }

void __VERIFIER_assert(int cond) //@ requires (cond != 0); 
//@ ensures (cond != 0);
{
  if (!(cond)) {
    ERROR: {reach_error();abort();}
  }
  return;
}

extern _Bool __VERIFIER_nondet_bool();//@ requires true; 
//@ ensures true;


int main()//@ requires module(n_c11__verifast_instrumented_modified, true); 
//@ ensures junk();
{
   int a[5];
   unsigned int len=0;

   int i;


   while(__VERIFIER_nondet_bool())//@ invariant (len < 5);
{
     
      if (len==4)
         len =0;
      
      a[len]=0;

      len++;
   }
   __VERIFIER_assert(len>=0 && len<5);
   return 1;

   
}