题解

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

int n,m;
int main(){
    cin >> n >> m;
    for(int i = 1;i <= n * 2 + 1;i++){
        for(int j = 1;j <= m * 2 + 1;j++){
            if(i % 2){
                if(j % 2)cout << "+";
                else cout << "-";
            }else{
                if(j % 2)cout << "|";
                else cout<<" ";
            }
        }cout<<endl;
    }
    return 0;
}