text: function B(input) {
    const array = input.split('\n');
  
    for (let i = 0; i < array.length; i++) {
      for (let j = i+1; j < array.length; j++) {
        const string1 = array[i];
        const string2 = array[j];
        let flag = false;
        let k;
  
        for (k = 0; k < string1.length; k++) {
          if (string1[k] !== string2[k]) {
            if (flag === false) {
              flag = k;
            } else {
              flag = false;
              break;
            }
          }
        }
  
        if (flag !== false) {
          return string1.slice(0, k) + string1.slice(k+1);
        }
      }
    }
  }
  