Exam preparation problem

function solve(input) {

    let minPoorGrades = Number(input.shift());

    let allGrades = 0;
    let examCount = 0;
    let lastExam = "";
    let poorGrades = 0;

    let currentExam = input.shift();
    let currentGrade = Number(input.shift());

    let isEnough = (currentExam !== "Enough");
    let isPoorGradesHit = (poorGrades < minPoorGrades);

    while (isEnough && isPoorGradesHit) {

        if (currentGrade <= 4) {
            poorGrades++;
        }

        lastExam = currentExam;
        examCount++;
        allGrades += currentGrade;

        // end of the current exam

        currentExam = input.shift();
        currentGrade = Number(input.shift());

        isEnough = currentExam !== "Enough";
        isPoorGradesHit = (poorGrades < minPoorGrades);
    }


    if (poorGrades < minPoorGrades) {
        let averageGrade = (allGrades / examCount).toFixed(2);

        console.log(`Average score: ${averageGrade}`);
        console.log(`Number of problems: ${examCount}`);
        console.log(`Last problem: ${lastExam}`);
    } else {
        console.log(`You need a break, ${poorGrades} poor grades.`)
    }
}