#include<stdio.h>
#include<stdlib.h>
#include<math.h>
#include<assert.h>
#define REP(i,a,b) for(i=a;i<b;i++)
#define rep(i,n) REP(i,0,n)

#define ll long long

int N, M, A[50][50];
ll dp_max[50][50][50][50];
ll sum_row[50][50][50], sum_col[50][50][50], allSum;

/* precalculation: calculate the sum of segments */
void calcSum(void){
  int i, j, k;
  rep(i,N) rep(j,M){
    sum_row[i][j][i] = sum_col[i][j][j] = A[i][j];
    REP(k,i+1,N) sum_row[i][j][k] = sum_row[i][j][k-1] + A[k][j];
    REP(k,j+1,M) sum_col[i][j][k] = sum_col[i][j][k-1] + A[i][k];
  }
  allSum = 0;
  rep(i,N) rep(j,N) allSum += A[i][j];
}

/* calculate the number of candies of the fast/last row/col when the current board is (x1, y1) - (x2, y2) */
ll getUp   (int x1, int y1, int x2, int y2){ return sum_col[x1][y1][y2]; }
ll getDown (int x1, int y1, int x2, int y2){ return sum_col[x2][y1][y2]; }
ll getLeft (int x1, int y1, int x2, int y2){ return sum_row[x1][y1][x2]; }
ll getRight(int x1, int y1, int x2, int y2){ return sum_row[x1][y2][x2]; }

/* calculate Alice's move */
/* return the number of candies which Alice gets in the current move */
/* dx1, dy1, dx2, dy2 denote erasing row/col */
ll AliceMove(int x1, int y1, int x2, int y2, int *dx1, int *dy1, int *dx2, int *dy2){
  ll up, down, left, right, mx;

  up = getUp(x1,y1,x2,y2);
  down = getDown(x1,y1,x2,y2);
  left = getLeft(x1,y1,x2,y2);
  right = getRight(x1,y1,x2,y2);

  mx = up;
  if(mx > down) mx = down;
  if(mx > left) mx = left;
  if(mx > right) mx = right;

  *dx1 = *dy1 = *dx2 = *dy2 = 0;
  if(mx == up) *dx1 = 1;
  else if(mx == down) *dx2 = -1;
  else if(mx == left) *dy1 = 1;
  else if(mx == right) *dy2 = -1;

  return mx;
}

/* calculate maximum Bob's candies with the current board (x1,y1)-(x2,y2), (memorized) */
/* Alice moves first:) */
ll solve_max(int x1,int y1,int x2,int y2){
  int i, j, k;
  ll left, right, up, down;
  int dx1, dy1, dx2, dy2;
  ll res=0, tmp;

  if(x1 > x2 || y1 > y2) return 0;
  if(dp_max[x1][y1][x2][y2] >= 0) return dp_max[x1][y1][x2][y2];

  AliceMove(x1,y1,x2,y2,&dx1,&dy1,&dx2,&dy2);
  x1 += dx1; x2 += dx2; y1 += dy1; y2 += dy2;
  if(x1 > x2 || y1 > y2){
    x1 -= dx1; x2 -= dx2; y1 -= dy1; y2 -= dy2;
    return 0;
  }

  tmp = solve_max(x1+1, y1, x2, y2) + getUp(x1, y1, x2, y2);
  if(res < tmp) res = tmp;
  
  tmp = solve_max(x1, y1, x2-1, y2) + getDown(x1, y1, x2, y2);
  if(res < tmp) res = tmp;

  tmp = solve_max(x1, y1+1, x2, y2) + getLeft(x1, y1, x2, y2);
  if(res < tmp) res = tmp;

  tmp = solve_max(x1, y1, x2, y2-1) + getRight(x1, y1, x2, y2);
  if(res < tmp) res = tmp;
  
  x1 -= dx1; x2 -= dx2; y1 -= dy1; y2 -= dy2;
  return dp_max[x1][y1][x2][y2] = res;
}

int main(){
  int T;
  int i, j, k, l;
  ll res, tmp1, tmp2;

  assert( scanf("%d",&T)==1 );
  assert( 1 <= T && T <= 25 );

  while(T--){
    assert( scanf("%d%d",&N,&M)==2 );
    assert( 1<=N && N<=50 && 1<=M && M<=50 );

    rep(i,N) rep(j,M) assert( scanf("%d",A[i]+j)==1 );
    rep(i,N) rep(j,M) assert( 0<=A[i][j] && A[i][j] <= 1000000000 );

    calcSum();
    rep(i,N) rep(j,M) REP(k,i,N) REP(l,j,M) dp_max[i][j][k][l] = -1;

    res = 0;
    tmp1 = solve_max(0, 0, N-1, M-1); /* the maximum number of candies which Bob gets */
    tmp2 = allSum - tmp1;             /* the number of Alice's candies */

    if(tmp1 == tmp2) res = tmp1 + tmp2; /* both are winner*/
    else if(tmp1 > tmp2) res = tmp1;    /* Bob wins */
    else res = tmp2;                    /* Alice wins */

    printf("%lld\n",res);
  }

  return 0;
}