title: Asking ideas of a codeforces problem (Problem-483A Counterexample)
body: <p>Problem link: <a href="http://codeforces.com/problemset/problem/483/A" rel="nofollow noreferrer">http://codeforces.com/problemset/problem/483/A</a></p>
  
  <blockquote>
    <p>You need to find three numbers (a, b, c), such that l ≤ a &lt; b &lt; c ≤ r, pairs (a, b) and (b, c) are coprime, and pair (a, c) is not coprime. The single line contains two positive space-separated integers l, r (1 ≤ l ≤ r ≤ 10^(18); r - l ≤ 50).</p>
  </blockquote>
  
  <p>I want to know ideas of solving this problem.</p>
  
  <p>Edit:</p>
  
  <p>Here is my attempt:</p>
  
  <pre><code>#include&lt;iostream&gt;
  #include&lt;cstdlib&gt;
  using namespace std;
  int main()
  {
      int l, r, i, c;
      cin &gt;&gt; l &gt;&gt; r;
      c = r - l;
  
      if(c &lt;= 50)
      {
          if(c &gt;= 2)
          {
              for(i = l; i &lt;= r; i++)
              {
                  if(i % 2 == 0)
                  {
                      cout &lt;&lt; i &lt;&lt; " " &lt;&lt; i+1 &lt;&lt; " " &lt;&lt; i+2 &lt;&lt; endl;
                      break;
                  }
              }
          }
          else if(c &lt;= 1)
          {
              cout &lt;&lt; "-1" &lt;&lt; endl;
          }
      }
  }
  </code></pre>
  
  <p>What is wrong with my code? The error message on the site is  </p>
  
  <pre><code>Probably, the solution is executed with error 'uninitiaized value usage' on the line 10
  </code></pre>