void Food()
  {

 if(head.x==food.x&&head.y==food.y||head.x+1==food.x+1&&head.y+1==food.y+1||
 head.x+2==food.x+2&&head.y+2==food.y+2)
   {
    length++;
    time_t a;
    a=time(0);
    srand(a);
    food.x=rand()%70;
    if(food.x<=10)
    food.x+=11;
    food.y=rand()%30;
    if(food.y<=10)

        food.y+=11;
}
else if(food.x==0)
    food.x=rand()%70;
    if(food.x<=10)
        food.x+=11;
    food.y=rand()%30;
    if(food.y<=10)
        food.y+=11;
 }
 }