process.stdin.resume();
process.stdin.setEncoding('ascii');

var input_stdin = "";
var input_stdin_array = "";
var input_currentline = 0;

process.stdin.on('data', function (data) {
    input_stdin += data;
});

process.stdin.on('end', function () {
    input_stdin_array = input_stdin.split("\n");
    main();    
});

function readLine() {
    return input_stdin_array[input_currentline++];
}

/////////////// ignore above this line ////////////////////

function main() {
    var n = parseInt(readLine());
    var xval,yval,xy=true,yy=true;
    for(var a0 = 0; a0 < n; a0++){
        var x_temp = readLine().split(' ');
        var x = parseInt(x_temp[0]);
        var y = parseInt(x_temp[1]);
        if(a0 == 0) {
            xval = x;
            yval = y;
        }
        if(x != xval) xy = false;
        if(y != yval) yy = false;
    }
    if(xy || yy) console.log("YES");
    else console.log("NO");
}