Envío 5686

Código

async function readInput() {
    let inputStr = '';

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

    for await (const line of rl) {
        inputStr += line + '\n';
    }

    inputStr = inputStr.substr(0, inputStr.length - 1);

    return inputStr;
}

(async () => {
    const input = await readInput();
    let letters = [];

    for (i of input) {
        if (letters.includes(i)) {
            console.log('yes');
            return;
        }
        letters += i;
    }

    console.log('no');
})();