//Do not declare variable marks.
//Write your code below this line.
function marking (marks) {
    if (marks>90){console.log("AA");}
    else if (marks > 80) { console.log ("AB");}
    else if (marks > 70) { console.log ("BB");}
    else if (marks > 60) { console.log ("BC");}
    else if (marks > 50) { console.log ("CC");}
    else if (marks > 40) { console.log ("CD");}
    else if (marks > 30) { console.log ("DD");}
    else{ console.log("FF");}
}

marking (100);