#include<bits/stdc++.h>

using namespace std;

const int maxn = ;

int a[][maxn];

int *b[];

//#define LOCAL

int main()

{

#ifdef LOCAL

    freopen("in.txt","r",stdin);

#endif

    int R,C;

    while(scanf("%d%d",&R,&C), R){

        for(int i = R; i--;){

            for(int j = C; j--;){

                scanf("%d",a[i]+j);

                a[i+R][j] = a[i][j]^;

            }

        }

        int ans = ;

        for(int S = <<R; --S >= ;){

            for(int i = ; i < R; i++){

                b[i] = a[i + (S>>i&?R:)];

            }

            int cur = ; //b[0] b[1]

            for(int j = ; j < C; j++){

                int cnt = ;

                for(int i = ; i < R; i++){

                    if(b[i][j]) cnt++;

                }

                cur += max(cnt,R-cnt);

            }

            ans = max(cur,ans);

        }

        printf("%d\n",ans);

    }

    return ;

}