function processData(input) {
    //Enter your code here
    
    var i=0;
    var j=0;
    var inputArr=input.split("\n");
    var coordArray=new Array();
    var tempArray;
    
    var lineNumber=1;
    var numberOfCoordinates=Number(inputArr[1]);
    var numberOfTests=Number(inputArr[0]);
    
    //numArray=inputArr[1].split(" ");
    
    for(i=0;i<numberOfTests;i++)
    {
        numberOfCoordinates=Number(inputArr[lineNumber]);
        lineNumber++;
        coordArray[i]=new Array();
        
        for(j=0;j<numberOfCoordinates;j++)
        {
            tempArray=inputArr[lineNumber].split(" ");
            coordArray[i][j]={x:Number(tempArray[0]),y:Number(tempArray[1])};
            //process.stdout.write(coordArray[i][j].x+" "+coordArray[i][j].y+"\n");
            lineNumber++;
        }
        //process.stdout.write("\n");
        
    }
    
    var minX=0;
    var minY=0;
    var maxX=0;
    var maxY=0;
    var pointOK=false;
    
    for(i=0;i<coordArray.length;i++)
    {
        minX=9999999;
        minY=9999999;
        maxX=0-9999999;
        maxY=0-9999999;
        for(j=0;j<coordArray[i].length;j++)
        {
            if(coordArray[i][j].x<minX)
            {
                minX=coordArray[i][j].x;
            }
            if(coordArray[i][j].x>maxX)
            {
                maxX=coordArray[i][j].x;
            }
            if(coordArray[i][j].y<minY)
            {
                minY=coordArray[i][j].y;
            }
            if(coordArray[i][j].y>maxY)
            {
                maxY=coordArray[i][j].y;
            }
        }
        
        //Find out of all points are on one line - if so, ok
        //Find out if all the points are on all four lines
        //Each point must share the y (vertical) or x(horizontal) and fall between min and max values
        pointOK=true;
        j=0;
        while(j<coordArray[i].length && pointOK==true)
        {
            pointOK=false;
            if(pointOK==false && coordArray[i][j].x>=minX && coordArray[i][j].x<=maxX && (coordArray[i][j].y==minY || coordArray[i][j].y==maxY))
            {
                pointOK=true;
            }
            
            if(pointOK==false && coordArray[i][j].y>=minY && coordArray[i][j].y<=maxY && (coordArray[i][j].x==minX || coordArray[i][j].x==maxX))
            {
                pointOK=true;
            }
            
            j++;
        }
        
        if(pointOK==false)
        {
            process.stdout.write("NO\n");
        }
        else
        {
            process.stdout.write("YES\n");
        }
    }
    
    
} 

process.stdin.resume();
process.stdin.setEncoding("ascii");
_input = "";
process.stdin.on("data", function (input) {
    _input += input;
});

process.stdin.on("end", function () {
   processData(_input);
});