#include<bits/stdc++.h>
using namespace std;
int m,n,a[210][210],ans=0,sx,sy;
inline int read()
{
    int x=0,f=1;
    char ch=getchar();
    while(ch<'0'||ch>'9')
    {
        if(ch=='-')
            f=-1;
        ch=getchar();
    }
    while(ch>='0' && ch<='9')
        x=x*10+ch-'0',ch=getchar();
    return x*f;
}
int main()
{
	m=read();
	n=read();
	for(int i=1;i<=m;++i)
	{
		for(int j=1;j<=n;++j)
		{
			a[i][j]=read();
		}
	}
	sy=m%3==0?2:1;
	sx=n%3==0?2:1;
	for(int i=sy;i<=m;i+=3)
	{
		for(int j=sx;j<=n;j+=3)
		{
			ans+=a[i][j];
		}
	}
	cout<<ans<<endl;    
}