// Divisible
// Sample code to perform I/O:

process.stdin.resume();
process.stdin.setEncoding("utf-8");
var stdin_input = "";

process.stdin.on("data", function (input) {
    stdin_input += input;                               // Reading input from STDIN
});

process.stdin.on("end", function () {
   main(stdin_input);
});

function main(input) {
    var data= input.toString().split("\n");

    process.stdout.write(divisible(data[1], parseInt(data[0])));
           // Writing output to STDOUT
}

// Warning: Printing unwanted or ill-formatted data to output will cause the test cases to fail



// Write your code here
// Sample code to perform I/O:
//Enter your code here

function divisible(input,n) {
   
    const arr = input.split(" ");
    let firstHalf = arr.slice(0,n/2);
    let secondHalf = arr.slice(n/2, n);

   
    let sumOdd = 0;
    let sumEven =0;

    let number= "";
    for (let i=0; i<n/2; i++) {
        number = number + firstHalf[i].substr(0,1);
        
    }

    for (let i=0; i<n/2; i++) {
        number = number + secondHalf[i].substr(secondHalf[i].length-1,1);
        
    }

    for (let i=0; i<n; i++) {
        let digit = parseInt(number.substr(i,1),10);
   
        if (i % 2 == 0) {
            sumOdd = sumOdd + digit;
        } else {
            sumEven = sumEven + digit;
        }
    } 

   
    if ((sumOdd - sumEven) % 11 == 0) {
        return 'OUI'
    } else { return "NON"};
    

    

}