# 1) variable number of arguments

int sum()
{
  buf = 0;
  for (i = 0; i < argc; i++) {
    buf += argv[i];
  }
  return buf;
}

a = sum(1);
b = sum(1,2);
c = sum(1,2,3);

if (a != 1 || b != 3 || c != 6) exit(1);
