为什么输出不对

#include<iostream>
#include<cstdio>
using namespace std;
int main(){
	int n;
    cin>>n;
    char a='|';
    char b='a';
    char c='-';
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n-1;j++){
            if(j==n||j==1)
                cout<<a;
            if(i==3&&j==2)
                cout<<c;
            if(i==3&&j==3)
                cout<<c;
            if(i==3&&j==4)
                cout<<c;
            else
                cout<<b;
        }
        cout<<endl;
    }
	return 0;
}