title: Using bitwise operators to change all bits of the most significant byte to 1
body: <p>Let's suppose I have an <code>unsigned int x = 0x87654321</code>. How can I use bitwise operators to change the most significant byte (the leftmost 8 bits) of this number to 1?</p>
  <p>So, instead of <code>0x87654321</code>, I would have <code>0xFF654321</code>?</p>