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.toFixed(2)}`)
    }

    }