function melrahShake(input) {
   let message = input.shift();
   let pattern = input.shift();
   let shakeIt = 0;

   while (pattern.length > 0) {
     const firstIndex = message.indexOf(pattern);
     const lastIndex = message.lastIndexOf(pattern);

     if (firstIndex > -1 && lastIndex > -1 && firstIndex !== lastIndex) {
       message = message.split('');
       message.splice(lastIndex, pattern.length);
       message.splice(firstIndex, pattern.length);
       message = message.join('');

       const patternCharToReplace = pattern[Math.floor(pattern.length / 2)];
       pattern = pattern.replace(patternCharToReplace, '');
       console.log('Shaked it.');
     } else {
       break;
     }
   }
   console.log('No shake.');
   console.log(message);
 }