Envío 3536

Código

const readline = require('readline');
const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout
});

function hasRepeatedLetters(string){
  const letters = string.split('');
  const uniqueLetters = new Set(letters);
  return uniqueLetters.size !== letters.length;
}

rl.on("line", (line) => {
 console.log(
   hasRepeatedLetters(line) ? "yes" : "no"
 );
})