import math if name == 'main': n = int(input()) a = 0 m = 10**n for i in range(1, n+1): m = math.floor(math.log10(i))+1 m = 10**m a = a*m + i print(a)

thats how it is done without print trick

import math
if __name__ == '__main__':
    n = int(input())
    a = 0
    m = 10**n
    for i in range(1, n+1):
        m = math.floor(math.log10(i))+1
        m = 10**m
        a = a*m + i
    print(a)

for i in range(n): print(i + 1, end='')

for i in range(1, n+1): print(i, end='')

Since this is looking for a solution without using any strings, I think even list concatenation doesn't count as a valid one. I think they are expecting more or less something along the lines of:

if __name__ == '__main__':
    n = int(input())
    a = 0;
    for i in range(1, n+1):
        if (i > 99):
            a = a*1000 + i
        elif (i > 9):
            a = a*100 + i
        else:
            a = a*10 + i
    
    print(a)