public class Solution {
    public boolean isSameTree(TreeNode p, TreeNode q) {
        if(p==null&&q==null)
        {
            return true;
        }
        if(p==null||q==null)
        {
            return false;
        }
        if(p.val==q.val)
        {
            return isSameTree(p.left,q.left)&&isSameTree(p.right,q.right);
        }
        else
        {
            return false;
        }
        
    }
}