CODE_GEN_STD_DBMS.py

"""
In DataBase Management Systems, we need to generate the keys for records created.In many cases, a key is generated by generating a non-negative integer 
and is standardized under a string with fixed length L (by filling characters 0 at the beginning of the integer util the length is equal to L).
For example, if the fixed-length L is 5, the key generated from 123 is the string 00123.
Given a positive integer n and L, and a sequence of integers a1, a2, ..., an.
Write a program for generating corresponding keys k1, k2, ..., kn. 

Input:
      Line 1: contains n and L (1 <= n <= 1000000, 2 <= L <= 50)
      Line i+1 (i = 1,...,n): contains ai (1 <= ai <= 2000000), ai < 10^L
Output:
      Line i (i = 1,..., n): contains the key ki

Example
Input:
      5
      6
      54
      39
      40
      78
      1
Output:
      000054
      000039
      000040
      000078
      000001
"""

n, L = [int(i) for i in input().split()]
p = []
for i in range(n):
    p.append(input())

for i in range(n):
    l = len(p[i])
    print("0"*(L-l) + p[i], end = "\n")