求调

	#include<bits/stdc++.h>
	using namespace std;
	int sum[16379][16379]; 
	int main(){
		long long n,m,x,y,f,cnt=0;
		cin>>n>>m;
		for(long long i=1;i<=n;i++)
		{
			cin>>x>>y>>f;
			if(sum[x][y]==0)
				sum[x][y]=sum[x-1][y]+sum[x][y-1]-sum[x-1][y-1]+f;
			else
				sum[x][y]=sum[x][y]+f;
		}
		for(long long i=1;i<=x;i++)
			for(long long j=1;j<=y;j++)
			{
				if(sum[i][j]-sum[i-m][j]-sum[i][j-m]+sum[i-m][j-m]>cnt)
					cnt=sum[i][j]-sum[i-m][j]-sum[i][j-m]+sum[i-m][j-m];
			}
		cout<<cnt;
	return 0;
}