# n=int(input())
# i=1
# s=0
# while True:
# s+=i
# if s>=n:
# print(i)
# break
# i += 1
# n, m=input().split()
# n=int(n)
# m=int(m)
# for i in range(1, n+1):
# for j in range(1, m+1):
# print(i,j)
# n=int(input())
# for i in range(1, n+1):
# if i%10==3 or i%10==6 or i%10==9:
# print("X", end=' ')
# else:
# print(i)