Subdividing a column

[mesh01]

what have you tried?

EDIT
For now I can only read the column of numbers from "input.txt" file and write 4 files for the 4 subdivisions:

input.txt file:

5 
77 
1
-4
9
17
13
2
1
5
63
8

#python3.6
import numpy as np   

d = np.loadtxt('input.txt')

A= 4
B= 2
C= 5
D= 1

with open('output1.txt', 'w') as f_out:
    for i in range(0,A):
        f_out.write(f"{d[i]}\n")
         
with open('output2.txt', 'w') as f_out:   
    for i in range(A,A+B):
        f_out.write(f"{d[i]}\n")

with open('output3.txt', 'w') as f_out:
    for i in range(A+B,A+B+C):
        f_out.write(f"{d[i]}\n")
         
with open('output4.txt', 'w') as f_out:   
    for i in range(A+B+C,A+B+C+D):
        f_out.write(f"{d[i]}\n")

output1.txt file:

Output:
5
77
1
-4

output2.txt file:

Output:
9
17

output3.txt file:

Output:
13
2
1
5
63

output4.txt file:

Output:
8

But I'm trying to write only one text file with 4 columns.

Bye,

m.