#include<iostream>
using namespace std;
int main()
{
	int m, n;
	int student[110][110]={};
	cin>>m>>n;
	for(int i=1;i<=m;++i)
	{
		for(int j=1;j<=n;++j)
		{
			cin>>student[i][j];
		}
	}
	int find_s=0;
	int dir[8][2]={{-1, 0}, {1, 0}, {0, -1}, {0, 1}, {-1, -1}, {-1, 1}, {1, -1}, {1, 1}};
	for(int i=1;i<=m;++i)
	{
		for(int j=1;j<=n;++j)
		{
			int x = i, y = j;
			bool fail = true;
			for(int d=0;d<8;++d)
            {
                if(student[x][y]==student[x+dir[d][0]][y+dir[d][1]])
                {
                    fail=false;
                    break;
                }
            }
            if(fail)
            {
                find_s+=1;
            }
		}
	}
	cout<<find_s<<endl;
}