let s=50;
let col;
let row;
function setup() {
  createCanvas(400, 400);
}

function draw() {
  background(220);
  for (let i = 0; i < 8; i++) {
    for (let j = 0; j < 8; j++) {
      fill(0,140,0);
      stroke(0);
      rect(j*s,i*s,s,s);
      if(col==j&&row==i){
        fill(255);
        noStroke();
       ellipse(j*s+25,i*s+25,40,40); 
      }
    }
  }
  
}


function mousePressed(){
  col=floor(mouseX/s);
  row=floor(mouseY/s);
}