#include<stdio.h>  const int inf = 99999;  const int N = 101;  int a[N][N],b[N][N],temp[N][N]; //a存储初始矩阵，b为目标状态矩阵  int n,m;  int need;//需要变换次数  void ChangeL(int x,int y)//变换列  {      if(x==y)return;      int i;      for(i=1;i<=n;i++)      {          int tt=temp[i][y];          temp[i][y]=temp[i][x];          temp[i][x]=tt;      }      need++;  }  void ChangeH(int x)//变换行  {      int i;      for(i=1;i<=m;i++)      {          temp[x][i]^=1;      }  }  bool Same(int x,int y) //判断列是否满足条件  {      int i;      for(i=1;i<=n;i++)          if(b[i][x]!=temp[i][y])return false;      return true;  }  int main()  {      int tests;      scanf("%d",&tests); //数据组数      while(tests--)      {          scanf("%d%d",&n,&m); //n行，m列          int i,j;          for(i=1;i<=n;i++)              for(j=1;j<=m;j++)              {                  scanf("%d",&a[i][j]);              }              for(i=1;i<=n;i++)                  for(j=1;j<=m;j++)                      scanf("%d",&b[i][j]);              int k;              int ans=inf; //ans存储最终答案，初始值为无穷大                for(k=1;k<=m;k++)//枚举各列为第一列              {                  for(i=1;i<=n;i++)                      for(j=1;j<=m;j++)                          temp[i][j]=a[i][j];                  need=0;                  ChangeL(1,k);                    //不满足的行，进行一次变换                  for(i=1;i<=n;i++)                  {                      if(temp[i][1]!=b[i][1])//该行不满足条件                      {                          ChangeH(i);//变换行                          need++;                      }                  }                  bool find;                  for(i=1;i<=m;i++)//检查每列是否满足条件                  {                      find=false;                      if(Same(i,i))                      {                          find=true;                          continue;                      }                      for(j=i+1;j<=m;j++)//寻找temp中与b的i列相同的列                      {                          if(Same(i,j))//temp 的 j列于b的i列相同                          {                              if(Same(j,j))continue;//temp的j列与b的j列相同                              ChangeL(i,j);//交换temp的i，j列                              find=true;                              break;                          }                      }                      if(find==false)//找不到该列对应列                      {                          break;                      }                  }                  if(find==true&&need<ans)                      ans=need;              }              if(ans<inf)                  printf("%d\n",ans);              else                  printf("-1\n");      }      return 0;  }