extern void __VERIFIER_error() __attribute__ ((__noreturn__));
void __VERIFIER_assert(int cond) {
  if (!(cond)) {
    ERROR: __VERIFIER_error();
  }
  return;
}
unsigned int __VERIFIER_nondet_uint();
int main() {
  unsigned int sn=0;
  unsigned int loop1=__VERIFIER_nondet_uint(), n1=__VERIFIER_nondet_uint();
  unsigned int x=0;
  while(1) {
    sn = sn + (2);
    x++;
    __VERIFIER_assert(sn==x*(2) || sn == 0);
  }
}