Creating unique order count for duplicate orders by account id and order id

Question

I'm trying to create a data set that will show me the duplicate transactions. The trouble I'm running into is when there are multiple orders on one order_id. The records that get assigned the 2s I would be considering the duplicate order.

data have;
input acct_id order_id;
datalines;
1 121
1 122
2 123
2 124
3 125
3 125
3 125
3 126
3 126
3 126

data want;
set have;
by acct_id order_id;
if first.acct_id then order_count = 1;
else order_count =2; 
run;

My desired output is below.

acct_id | order_id | order_count
1           121       1
1           122       2
2           123       1
2           124       2 
3           125       1
3           125       1
3           125       1
3           126       2
3           126       2
3           126       2

What I have coded out already I feel like is close but I can't get it figured out.