#include<bits/stdc++.h>
#define ll long long
#define il inline
#define pn putchar('\n')
#define maxint 2147483647
#define min(x,y) (x<y?x:y)
#define max(x,y) (x>y?x:y)
#define maxn 205
using namespace std;
int n,m,ans;
int a[maxn][maxn];
signed main()
{
    #ifndef ONLINE_JUDGE
    freopen("in.txt","r",stdin);
    #endif
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;i++)
        for(int j=1;j<=m;j++)
            scanf("%d",&a[i][j]);
    for(int i=n%3?1:2;i<=n;i+=3)
        for(int j=m%3?1:2;j<=m;j+=3)
            ans+=a[i][j];
    printf("%d",ans);
    return 0;
}