RT，赛时罚坐70min

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define N 1010
int a[N][N],s[N][N],n,q;
int get(int x1,int y1,int x2,int y2){
	int res=s[x2][y2];
	if(x1!=0)res-=s[x1-1][y2];
	if(y1!=0)res-=s[x2][y1-1];
	if(x1+y1!=0)res+=s[x1-1][y1-1];
	return res;
}
int find(int A,int B,int C,int D){
	int da=A,db=B;A%=n,B%=n;
	C-=(da-A),D-=(db-B);
	if(C<n&&D<n){
		return get(A,B,C,D);
	}
	if(C>=n)return find(A,B,n-1,D)+find(0,B,C%n,D)+1ll*(C/n-1ll)*find(0,B,n-1,D);
	if(D>=n)return find(A,B,C,n-1)+find(A,0,C,D%n)+1ll*(D/n-1ll)*find(A,0,C,n-1);
}
signed main(){
cin>>n>>q;
	for(int i=0;i<n;i++)for(int j=0;j<n;j++){
		char x;cin>>x;
		a[i][j]=(x=='B');
	}
	for(int i=0;i<n;i++){
		for(int j=0;j<n;j++){
			if(i)s[i][j]+=s[i-1][j];
			if(j)s[i][j]+=s[i][j-1];
			if(i&&j)s[i][j]-=s[i-1][j-1];
			s[i][j]+=a[i][j];
		}
	}
	while(q--){
		int A,B,C,D;cin>>A>>B>>C>>D;
		cout<<find(A,B,C,D)<<"\n";
	}
}