title: terminating with uncaught exception of type std::out_of_range: basic_string
body: <pre><code>#include &lt;iostream&gt;
  #include &lt;string&gt;
  using namespace std;
  int main() {
     string s;
      cin&gt;&gt;s;
      int i;
      char c;
      for(i=1;i&lt;=sizeof(s);i++){
          if((s.at(i)&gt;='a'&amp;&amp;s.at(i)&lt;='z')||(s.at(i)&gt;='A'&amp;&amp;s.at(i)    &lt;='Z')){
              c=c+4;
              if((s.at(i)&gt;'Z'&amp;&amp;s.at(i)&lt;'\136')||(s.at(i)&gt;'z')){
                  c=c-26;
              }
          }
      }
      cout&lt;&lt;c;
      return 0;
  }
  </code></pre>
  
  <p>//terminating with uncaught exception of type std::out_of_range: basic_string</p>