#include <iostream>
#include <vector>
using namespace std;
int main() {
int n;
cin>>n;
int ms[n][n]={};
for(int i=0; i<n; i++)
for(int j=0; j<n; j++)
cin>>ms[i][j];
vector<pair<int,int>>sr;
for(int i=0; i<n; i++)
for(int j=i+1; j<n; j++)
if(ms[i][j]==1) sr.push_back({i,j});
int m=sr.size();
for(int i=0; i<m; i++)
cout<<sr[i].first<<" "<<sr[i].second<<endl;
return 0;
}
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