''' Purpose: introduce nested looping.
        for a user-supplied n, loop n times where on the r-th iteration,
        the integers from 1 to r are printed out.
'''

# get n
reply = input( 'Enter number: ' )
n = int( reply )

# performed the repeated printing of a number series
for r in range( 1, n + 1 ) :
    
    # print the numbers from 1 to r