#include<fstream>
using namespace std;
ifstream fin("flip.in");
ofstream fout("flip.out");
const int NMAX = 17;

int Stack[NMAX], grid[NMAX][NMAX];
int rowsCnt, colsCnt, maxSum;

inline void readData(){

    fin >> rowsCnt >> colsCnt;

    int row, col;
    for(row = 1; row <= rowsCnt; ++row)
        for(col = 1; col <= colsCnt; ++col)
            fin >> grid[row][col];
}

inline void checkSum(){

    int sum = 0, row, col, rowSum;
    for(row = 1; row <= rowsCnt; ++row){

        rowSum = 0;
        for(col = 1; col <= colsCnt; ++col)
            rowSum += grid[row][col] * Stack[col];
        if(rowSum < 0)
            rowSum *= -1;
        sum += rowSum;
    }
    maxSum = max(maxSum, sum);
}

void BKT(int StackLvl){

    if(StackLvl > colsCnt)
        checkSum();
    else{

        Stack[StackLvl] = 1;
        BKT(StackLvl + 1);
        Stack[StackLvl] = -1;
        BKT(StackLvl + 1);
    }
}

int main(){

    readData();
    BKT(1);
    fout << maxSum;
}