import sys
sys.setrecursionlimit(1000000000)

#
# Solution Template for Human LCD II
# 
# Australian Informatics Olympiad 2026 Invitationals
# 
# This file is provided to assist with reading of input and writing of output
# for the problem. You may modify this file however you wish, or
# you may choose not to use this file at all.
#

# R and C are the dimensions of the display; R * C is at most 1000.
R = 0
C = 0
# A and B contain the initial and target colours. Both lists start from 0.
A = []
B = []
# The ith instruction changes cell (X[i], Y[i]) to colour V[i]; coordinates are
# 1-based.
L = 0
X = []
Y = []
V = []

# Read the two R by C grids.
R, C = map(int, input().strip().split())
for i in range(0, R):
  A.append(list(map(int, input().strip().split())))
for i in range(0, R):
  B.append(list(map(int, input().strip().split())))

# TODO: Construct at most one million legal instructions transforming A into B.
# For full marks, minimise the number of instructions.
# An empty instruction sequence is shown below; it is correct only when A
# equals B.
print(L)
for i in range(0, L):
  print(X[i], Y[i], V[i])