function schoolGrades(input) {
  let dict = new Map;

  for (const el of input) {
    let [nameOfStudent, ...grades] = el.split(" ")
// console.log(grades)


      // let avgGrades = grades / Number(tokens.length - 1)
      if (!dict.has(nameOfStudent)) {
          dict.set(nameOfStudent, grades);
      } else {
        let currentStudent = dict.get(nameOfStudent);
          currentStudent.push(...grades)
          dict.set(nameOfStudent,currentStudent)
      }

  }
  // console.log(dict)
let sorted = Array.from(dict).sort((a,b)=> a[0].localeCompare(b[0]));




  for (const [nameOfStudent, grades] of sorted) {
    let avgGrades = 0
    for(let el of grades){
      el = Number(el)
      avgGrades+=el
    }
    avgGrades /= grades.length;
      console.log(`${nameOfStudent}: ${avgGrades.toFixed(2)}`);

  }
}