/**
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⣀⣤⡤⠤⣤⣄⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⡴⠛⠉⠀⠀⠀⠀⠈⠙⢷⣄⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣠⠟⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠙⣆⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣰⠶⣄⡀⠀⠀⠀⢠⡟⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢹⡆⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢰⡏⠀⠀⠉⠛⠶⣤⣸⡇⠀⠀⠀⠀⣀⣤⣶⣶⠒⠒⠒⠶⣬⡇⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⣀⣤⠴⠶⣿⠀⠀⠀⠀⠀⠀⠈⠉⠉⠛⠒⠶⢿⣭⣀⡀⢻⡀⠀⠀⢠⡿⠃⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⣤⠶⠛⠋⠁⠀⠀⢸⠃⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠈⠉⠛⠷⣴⣞⠛⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣀⡴⠞⠉⠀⠀⠀⠀⠀⠀⢰⣿⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠉⠛⢦⣄⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣠⠞⠋⠀⠀⠀⠀⢀⡤⠠⡄⠀⢰⡏⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠙⠿⣄⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣠⡞⠁⠀⠀⠀⠀⣠⠖⠋⠀⣸⠇⠀⢸⡇⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⠀⢀⡀⠀⠀⠀⠀⠀⠀⢦⡀⠀⠀⠀⠸⣷⣄⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⡼⠋⠀⠀⠀⠀⢀⣴⠋⢀⢀⡴⠋⠀⢀⣼⡇⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣽⠀⣼⢿⡄⠀⠀⠀⠀⣆⠀⠉⢦⡀⠀⠀⠀⠘⢧⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣠⡟⠁⠀⠀⠀⠀⣠⠟⠇⠀⠈⠉⠁⠀⣀⣾⣿⡇⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡟⢰⠏⠀⠻⣄⠀⠀⠀⠹⣄⣰⠟⠁⠀⠀⠀⠀⠀⢻⡄⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⣠⣾⡟⠀⢀⣀⡖⠀⣰⠏⠀⠀⠀⠀⠀⢀⣼⣿⠋⠸⡇⠀⠀⠀⠀⠀⠀⠀⠀⠀⢸⣧⡟⠀⠀⠀⠹⣦⠀⠀⠀⠀⠁⠀⣶⠀⠀⣴⠛⢧⠀⢻⡄⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⣠⠞⣩⡟⠀⠀⠈⠉⠀⢀⡟⠀⠀⢀⣀⣠⣤⣾⡿⠗⠒⠚⣿⠠⣤⠀⠀⠀⠀⠀⠀⠀⢸⣿⠓⠒⠲⠶⠶⠾⢷⣤⣀⣀⠀⠀⠙⣧⠀⠹⣆⣼⠃⠀⢷⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⢀⡴⠟⢁⡼⣿⠁⠀⠀⠀⠀⠀⢸⠃⠀⠀⠈⠉⢠⡾⠋⠀⠀⠀⠀⠸⣆⠙⣧⡀⠀⠀⠀⠀⠀⢸⡇⠀⠀⠀⠀⠀⠀⠀⠻⣆⠉⠁⠀⠀⢹⡄⠀⠈⠁⠀⠀⠘⣷⢦⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⣠⡶⠋⢀⡴⠋⢰⡏⠀⠀⠀⠀⠀⠀⢸⠀⠀⠀⠀⣠⠟⠀⠀⠀⠀⠀⠀⠀⢻⡄⢸⣷⣄⠀⠀⠀⠀⢸⡇⠀⠀⠀⠀⠀⠀⠀⠀⠈⢳⣄⠀⠀⠸⣧⠀⠀⠀⠀⠀⠀⢿⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⢰⣾⡥⠴⠞⠋⠀⠀⣼⠀⠀⠀⠀⠀⠀⠀⣸⠀⠀⠀⣰⠏⠀⠀⠀⠀⠀⠀⠀⠀⠀⢻⡄⣷⠙⠷⣄⡀⠀⢸⡇⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠙⢷⣄⠀⣿⠀⠀⠀⠀⠀⠀⢸⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⣿⡆⠀⠀⠀⠀⠀⠀⢸⡄⠀⣼⢏⣀⣤⣶⣦⣤⣶⣶⣶⣶⣶⣿⣿⣾⡆⠀⠈⠻⢦⣼⡇⢰⣶⣶⣶⣶⣶⣶⣶⣤⣤⣤⣦⠙⢧⣿⠀⠀⠀⠀⠀⠀⢸⡄⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⣿⡇⠀⠀⠀⠀⠀⠀⠘⣇⣼⠏⠘⣿⡿⢿⣿⣿⣿⣿⣿⡏⠉⠉⠉⠙⠃⠀⠀⠀⠀⠉⠁⠘⠛⢻⣿⣿⣿⣿⣿⣟⠛⢛⠷⠀⠀⣿⠀⠀⠀⠀⠀⠀⢸⡇⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⡟⣷⠀⠀⠀⠀⠀⠀⠀⢻⡏⠀⠀⠀⠀⣸⣿⣿⣿⣿⣿⣷⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣾⣿⣿⣿⣿⣿⡇⠀⠀⠀⠀⢰⡏⠀⠀⠀⠀⠀⠀⣾⡇⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⣷⢹⣆⠀⠀⠀⠀⠀⠀⠈⣷⠀⠀⠀⠀⢹⣿⣿⣿⣿⣿⣿⡄⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣿⣿⣿⣿⣿⣿⡇⠀⠀⠀⠀⣾⠀⠀⠀⠀⠀⠀⢰⣿⡇⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⢿⠘⣿⣆⠀⠀⠀⠀⠀⠐⠘⣧⠀⠀⠀⠘⢿⣿⣿⣿⣿⠏⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠙⢿⣿⣿⣿⡿⠃⠀⠀⠀⣼⠃⠀⠀⠀⠀⠀⣰⠟⠐⡇⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠸⣇⣿⠙⣧⣄⠀⠀⠀⠀⠀⠘⢧⡀⠀⠀⠈⢹⠿⢟⡋⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠙⢻⡿⠀⡀⠀⠀⣼⠃⠀⠀⠀⠀⣀⡾⠋⠀⣴⣷⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⢻⣿⠀⣿⠝⠳⣤⣀⡀⠀⠀⠈⢷⣤⠇⢠⡞⠠⠾⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢠⠟⠁⡾⠃⣠⡾⠃⠀⠀⣀⣤⠾⠋⠀⠀⠀⡿⣿⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠈⣿⣸⣿⠀⠀⠀⠉⠙⠓⡶⠦⠤⣿⡆⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠓⢰⡿⠤⠴⠶⣿⠉⠀⠀⠀⠀⠀⢠⡇⢸⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠈⣿⢻⠀⠀⠀⠀⠀⠃⣿⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢲⣄⠀⠀⠀⠀⠀⠀⠀⢀⣴⠆⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡟⠀⠀⠀⠀⠀⠀⢸⡇⣸⡇⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢠⡿⢸⡇⠀⠀⠀⠀⠀⢿⡄⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠈⠛⠲⠤⣤⠤⠴⠞⠋⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢰⡏⠀⠀⠀⠀⠀⠀⢸⠇⠈⣇⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣸⡇⢸⡇⠀⠀⠀⠀⠀⢸⣿⣦⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢿⡇⠀⠀⠀⠀⠀⠀⢺⢀⠀⢿⠀⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣸⢷⠛⣇⠀⠀⠀⠀⠀⠈⣿⠉⠻⣦⡀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣠⣾⣅⣸⠀⠀⠀⠀⠀⠀⢀⣿⢸⡀⢸⡇⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡿⠘⣀⣿⠀⠀⠀⠀⠀⢷⢸⡄⠀⠈⠙⠶⣤⣀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⣠⡴⠟⠁⠀⠈⣿⠀⠀⠀⠀⠀⠀⠈⡟⣼⡇⠀⣧⠀⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⢰⡇⠀⢿⢿⠀⠀⠀⠀⠀⠀⠈⣧⠀⠀⠀⠀⠀⠉⠛⠶⢤⣤⣀⣀⠀⣀⡀⠀⠀⠀⠀⠀⢀⣠⡴⠞⠋⠁⠀⠀⠀⠀⢀⡏⠀⠀⠀⠀⠀⠀⢠⡇⢹⣤⠀⢹⡄⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⣼⠀⠀⡿⢸⡆⠀⠀⠀⠀⠀⠀⢻⡆⠀⠀⠀⠀⠀⠀⠀⠀⣿⡿⠟⠋⠉⠁⠀⠀⠀⠀⠀⢸⠁⠀⠀⠀⠀⠀⠀⠀⠀⢸⠇⠀⠀⠀⠀⠀⠀⢸⡇⠈⣟⠀⠈⣷⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⢰⡟⠀⢰⡇⠘⡇⠀⠀⠀⠀⠀⠘⠀⣷⠀⠀⠀⠀⠀⠀⠀⠀⣿⠁⠀⠀⠀⠀⠀⠀⠀⠀⠀⢸⠀⠀⠀⠀⠀⠀⠀⠀⠀⡿⠆⠀⠀⠀⠀⠀⠀⣼⠁⠀⢻⡀⠀⠸⣇⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⣼⠁⠀⣼⠁⠀⣿⠀⠀⠀⠀⠀⠀⠀⠻⣇⣀⠀⠀⠀⠀⠀⠀⣿⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢸⡀⠀⠀⠀⠀⠀⠀⠀⣰⡇⠀⠀⠀⠀⠀⠀⠀⣿⡆⠀⠈⣷⡀⠀⢻⡄⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⢰⡇⠀⢀⡏⠀⠀⢻⠀⠀⠀⠀⠀⠀⠀⠀⢻⣦⣄⠀⠀⠀⠀⣠⡟⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠘⣧⠀⠀⠀⠀⠀⣠⣾⣿⠀⠀⠀⠀⠀⠀⢠⣠⡇⡇⠀⠀⠸⣯⡀⠀⢷⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⡾⠀⠀⣼⠁⠀⠀⠸⡇⠀⠀⠀⠀⠀⠀⠀⠀⢿⣽⡧⠴⢶⣿⣿⠖⠒⠛⠛⠃⠀⠀⠀⠚⠋⠉⠉⠉⠙⠓⠲⢾⡛⠻⣽⠃⠀⠀⠀⠀⠀⠀⢸⣿⣃⠀⠀⠀⠀⢹⣷⠀⠘⣧⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⣸⠃⠀⢸⡏⠀⠀⠀⢀⣿⠀⠀⠀⠀⢀⣀⠀⠈⠈⢷⠖⠚⠋⠁⢹⡇⠀⢀⣴⠶⠶⢦⣄⣀⣤⡶⠶⠤⠤⠤⠶⠾⠇⢰⡏⠀⠀⠀⠀⠀⠀⠻⣿⣿⣤⡀⠀⠀⠀⠀⢿⣀⠀⠸⣆⠀⠀⠀
⠀⠀⠀⠀⠀⢰⠏⠀⢀⡿⠀⠀⠀⣰⠟⢹⣿⡄⠀⠀⠀⠻⣄⠀⠀⠘⣷⣤⣄⣀⣈⡙⠛⢹⡷⢶⣦⣴⣾⣛⣻⢯⣴⣦⠴⠖⠃⠀⢀⡾⠀⠀⠀⠀⠀⠀⠀⢰⣿⡇⠀⠹⣆⠀⠀⠸⡞⣧⣆⠀⠹⣄⠀⠀
⠀⠀⠀⠀⢠⡟⠀⠀⡼⠁⠀⠀⣰⠏⠀⠈⣟⣧⠀⠀⠀⠀⢻⣆⠀⠀⠈⣧⡿⠀⠈⠉⠛⠛⣻⣿⡿⢿⣿⡍⠉⠀⠀⠀⠀⠀⠀⠀⡾⠁⠀⠀⠀⢀⣴⠀⠀⡾⣿⠁⠀⠀⠘⣧⠀⠀⢿⠘⣟⠀⠀⢻⡄⠀
⠀⠀⢀⣠⡟⠀⢀⡾⠃⠀⠀⣰⡏⠀⠀⠀⣻⠘⣧⠀⠀⠀⠀⢻⣷⡄⠀⠘⢷⡀⠀⠀⠀⠀⠩⣉⠁⠈⣛⡁⠀⠀⠀⠀⠀⠀⣀⣾⠁⠀⠀⣀⣠⣟⠁⠀⣠⣤⡟⠀⠀⠀⠀⠘⣧⡄⠘⡇⠙⣇⠀⠀⠻
*/
#include <bits/stdc++.h>
using namespace std;
#define i64 long long
#define ld long double
#define bit(n,i) ((n>>i)&1)
#define pii pair<int,int>
#define sz(x) (int)x.size()
#define FOR(i,a,b) for(int i=a; i<=b; i++)
#define FOD(i,a,b) for(int i=a; i>=b; i--)
#define fi first
#define se second
#define pb push_back
#define all(x) x.begin(),x.end()
#define __sumairu__ main()
#define die_hard_onimai_fan void seggs()
#define file(name) if(fopen(name".inp","r")){freopen(name".inp","r",stdin);freopen(name".out","w",stdout);}
#define brute(name) if(fopen(name".inp","r")){freopen(name".inp","r",stdin);freopen(name".ans","w",stdout);}
#define TIME (1.0*clock()/CLOCKS_PER_SEC)
#define FAST ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define ai(n) array<int,n>
#define dbg(x) {cerr<<#x<<' '<<x<<endl;}
#define dbgArr(arr,n) {cerr<<#arr;FOR(_i,1,n)cerr<<' '<<(arr)[_i];cerr<<endl;}
template <typename T,typename U>
ostream& operator<<(ostream &os,pair<T,U>p){
return os<<"{"<<p.fi<<", "<<p.se<<"}";
}
mt19937_64 rd(chrono::steady_clock::now().time_since_epoch().count());
i64 Rand(i64 l,i64 r)
{
i64 ans=l+1ll*rd()*rd()%(r-l+1);
assert(l<=ans&&ans<=r);
return ans;
}
//const i64 base=1e9+7;
//const i64 mod=(1ll<<53)+5;
#define i64 long long
#define debug 0
//const int mod=1e9+7;
//const int mod=998244353;
const int inf=1e9;
///check the limits, dummy
const int N=2003;
int n,m;
int a[N][N];
void swap_row()
{
FOR(j,1,m)
{
FOR(i,1,n/2)swap(a[i][j],a[n-i+1][j]);
}
}
void swap_col()
{
FOR(i,1,n)
{
FOR(j,1,m/2)swap(a[i][j],a[i][m-j+1]);
}
}
int ans;
int mn=inf,mx=-inf;
bool check(int x)
{
int lst=m;
FOR(i,1,n)
{
FOR(j,0,lst-1)if(a[i][j+1]-mn>x)
{
lst=j;
break;
}
FOD(j,m,lst+1)if(a[i][j]<mx-x)return 0;
}
return 1;
}
void cal()
{
int l=0,r=ans;
while(l<=r)
{
int mid=(l+r)/2;
if(check(mid))
{
ans=mid;
r=mid-1;
}
else l=mid+1;
}
}
die_hard_onimai_fan
{
cin>>n>>m;
FOR(i,1,n)FOR(j,1,m)
{
cin>>a[i][j];
mn=min(mn,a[i][j]);
mx=max(mx,a[i][j]);
}
ans=mx-mn;
cal();
swap_row();
cal();
swap_col();
cal();
swap_row();
cal();
cout<<ans<<'\n';
}
__sumairu__
{
FAST
file("");
int tt=1;//cin>>tt;
while(tt--)seggs();
cerr<<"\nTime elapsed: "<<TIME<<" s.\n";
}
/**
4 4
1 12 6 11
11 10 2 14
10 1 9 20
4 17 19 10
*/
