95 WA on #21

#include<bits/stdc++.h>
#define int long long
using namespace std;

int n,m;
int w[1314][1314];
int f[1314][1314][2];

int dfs(int x,int y,int from)
{
	if(x < 1 || x > n || y < 1 || y > m)
		return -0x3f3f3f;
		
	if(f[x][y][from] != -0x3f3f3f)
		return f[x][y][from];
		
	if(from == 0)
		f[x][y][from]=max(dfs(x+1,y,0),max(dfs(x,y-1,0),dfs(x,y-1,1)))+w[x][y];
	else
		f[x][y][from]=max(dfs(x-1,y,1),max(dfs(x,y-1,0),dfs(x,y-1,1)))+w[x][y];
	
	return f[x][y][from];
}

signed main()
{
    cin >> n >> m;
    
    for(int i=1;i<=n;i++)
    {
    	for(int j=1;j<=m;j++)
    	{
    		cin >> w[i][j];
    		f[i][j][0]=-0x3f3f3f;
    		f[i][j][1]=-0x3f3f3f;
		}
	}
	
	f[1][1][0]=f[1][1][1]=w[1][1];
	
	cout << dfs(n,m,1);
    
    return 0;
}