#include
using namespace std;
int main() {
int a[100][100];
int m,n,oddcol=2,evencol=1;
cin>>m>>n;
for(int i = 1; i <= m; i++){
for(int j = 1; j <=n; j++){
cin>>a[i][j];
}
cout<<endl;
}
while(evencol<=n){
for(int i = 1; i <= m; i++){
cout<<a[i][evencol]<<","<<" ";
}
evencol = evencol+2;
if(oddcol<=n){
for(int i = n; i > 0; i--){
cout<<a[i][oddcol]<<","" ";
}
}
oddcol = oddcol+2;
}
// cout<<“END”;
return 0;
}