#include <iostream>
using namespace std;
// 该算法适用于无向欧拉图找出具体的欧拉通路
// 适用于两个顶点间有多条线的 -- 邻接矩阵中将“1”设成“n”
int main()
{
	int n;
	cout << "please input the order of metrix: ";
	cin >> n;

	int ljMat[n + 1][n + 1]; //邻接矩阵
	for (int i = 1; i <= n; i++) //使用邻接矩阵表示图
	{
		for (int j = 1; j <= n; j++)
		{
			cin >> ljMat[i][j];
		}
	}

	int start = 1, present = start, tmp = 0;
	//算法思想：能不走桥就不走桥
	while (true)
	{
		int flag2 = 0, flag1 = 0;

		for (int j = 1; j <= n; j++) //遍历该点与其它所有点的邻接关系
		{
			if (ljMat[present][j] >= 2) //找到第一条非桥，就走它
			{
				flag2++;		 //记录是否存在非桥
				ljMat[present][j]--; //边是二元关系，两个点都要改变；包括了环的情况
				ljMat[j][present]--;
				cout << "(" << present << "," << j << ")"
					 << " "; //模拟走的道路
				present = j; //更新当前点
				break;		 //找到就进入下一个点
			}
			if (ljMat[present][j] == 1 && flag1 == 0) //记录第一个与当前点存在一条边（不一定是割边）的点
			{
				flag1++;
				tmp = j;
			}
		}

		if (flag2 == 0 && flag1 == 1) //只能走桥
		{
			ljMat[present][tmp]--;
			ljMat[tmp][present]--;
			cout << "(" << present << "," << tmp << ")"
				 << " ";
			present = tmp;
		}
		if (flag2 == 0 && flag1 == 0)
			break; //当矩阵为零矩阵时结束
	}
	return 0;
}