int colum[4] = {9,8,7,6};
int row[4] = {2,3,4,5};
void setup() {
  for(int i = 2; i <= 9; i++){
    pinMode(i, OUTPUT);
  }

  // put your setup code here, to run once:

}

void loop() {
  for(int i = 0; i < 4; i++){
    grid_y(i);
    delay(100);
  }

  // put your main code here, to run repeatedly:
}

void grid_y(int y){

}