# How to serially number the output ?

I want the output of the following code to be serially numbered as

(1)A combination is-------

(2)A combination is -------

(3)A combination is-------

and so on.

The code is :

```
# Write your matrix
H = matrix(2,2, [1, 1,1, -1])
n = 2 # Enter the order of the matrix H
V = GF(2)^(n^2)
R1=V.list()[1:]
#We are removing the all-zero list because not needed for our purpose
R2=R1[:-1]
#We are removing the all-ones list because not needed for our purpose
A = []
for v in R2:
A.append(matrix(ZZ,n,n,v))
# Forming n by n matrices from list in R2. Contains all 0,1 matrices.
B=[]
for a in A:
b=-a # Forming n by n matrices from A by taking their negative. Contains all 0,-1 matrices
B.append(b)
C = []
for a in A:
C.append(a)
for b in B:
C.append(b) #Union of A and B
test_sum = 4
test_comb = Combinations(C,test_sum)
# Here we are forming all "test_sum"-set combinations from C".
# That is, if test_sum =3, then test_comb, gives all 3 set combinations from C"
for t in test_comb:
if (sum(t)==H):
#Checking which combinations in test_sum give the sum = H and printing those
print("A combination is: ")
show(t)
print("\n")
```

Just introduce a counter that will increment with every printed combination.

Thanks a lot. I didn't know about the "Counter" thing. Saw on internet about it and applied it. Thanks a lot.

@max-alekseyev/ : could you turn your comment into an answer, in order to help future perusers of

`ask.sagemath.org`

with a similar question ?Also : why a "-1" to the question itself ? I's answer is not trivial for Sage (or Python) newbies...