# 1479 Matrix Eraser

import numpy as np
from sys import stdin
readline=stdin.readline

h,w=map(int,readline().split())
A=np.array([list(map(int,readline().split()))])
for _ in range(1,h):
    A=np.append(A,np.array([list(map(int,readline().split()))]),axis=0)

cnt=0
while True:
    maxA=np.max(A)
    if maxA==0:
        break

    atMaxA=np.where(A==maxA)
    rowBinCnt=np.bincount(atMaxA[0])
    colBinCnt=np.bincount(atMaxA[1])
    rowBinCntMax=np.max(rowBinCnt)
    colBinCntMax=np.max(colBinCnt)
    if rowBinCntMax>=colBinCntMax:
        selectedRow=np.where(rowBinCnt==rowBinCntMax)[0][0]
        A[selectedRow]=np.where(A[selectedRow]==maxA,0,A[selectedRow])
    else:
        selectedCol=np.where(colBinCnt==colBinCntMax)[0][0]
        A[:,selectedCol]=np.where(A[:,selectedCol]==maxA,0,A[:,selectedCol])
    cnt+=1

print(cnt)