function schoolGrades(input){

let students = {}

for (const line of input){
    let studentInfo = line.split(" ")
    let name = studentInfo.shift()
    let grades = studentInfo.map(x => Number(x))

    if(!students[name]){

        students[name] = []
    }

    students[name]= students[name].concat(grades)
}
let studentsEntries = Object.entries(students)
let sortedStudents = studentsEntries.sort((a,b)=> a[0].localeCompare(b[0])
);

for (let [name, grade] of sortedStudents){

    let sum = 0


    for (let grades of grade){
        sum+=grades

    }
  //  let avarageGrade = sum / grade.length
//console.log(`${name}: ${avarageGrade}`)
//} - Вариант 1
//Вариант с reduce
let avarageGrade = grade.reduce((a,b) => a+b )/grade.length
console.log(`${name}: ${avarageGrade.toFixed(2)}`)
}

}