title: Why is & used before a variable?
body: <p>Why is <code>&amp;</code> used here before <code>decks</code> (<code>scanf("%i", &amp;decks)</code>)? </p>
  
  <p>And if my input is any letter like 'k' then it shows an output like "1929597720". Why?</p>
  
  <pre><code>#include &lt;stdio.h&gt;
  
  int main(){
      int decks;
  
      puts("enter a number of decks:");
      scanf("%i", &amp;decks);
  
      if (decks&lt;1) {puts("Please enter a valid deck number");
          return 1;
      }
  
      printf("there are %i cards\n", (decks*52));
      return 0;
  }
  </code></pre>