extern void reach_error(void);
extern unsigned char __VERIFIER_nondet_uchar(void);
int myFunction() {
  unsigned char n = __VERIFIER_nondet_uchar();
  if (n == 0) {
    return 0;
  }
  unsigned char v = 0;
  unsigned int  s = 0;
  unsigned int  i = 0;
  //@ loop invariant s <= i * 255 && i <= 255 && s >= v;
  while (i < n) {
    v = __VERIFIER_nondet_uchar();
    s += v;
    ++i;
  }
  if (s < v) {
    reach_error();
    return 1;
  }
  if (s > 65025) {
    reach_error();
    return 1;
  }
  return 0;
}