program karcas;
Uses crt;
var a:array[1..100,1..100] of integer;
    Nnew:array[1..100] of boolean;
    Tree:array[1..2,1..100] of integer;
    Turn:array[1..100] of integer;
    n,i,j, u, d, numb:integer;
    inp ,outp : text;

procedure solve(v,q:integer);
var j:integer;
begin
   if d >= u then exit;
   j:=q;
   while (j <= n) and (numb < n-1) do
       begin
          if (a[v,j] <> 0) and Nnew[j] then
             begin
                Nnew[j]:=false;
                inc(numb);
                Tree[1,numb]:=v;Tree[2,numb]:=j;
                Turn[u]:=j;inc(u);
                solve(v,j+1);
                dec(u);Nnew[j]:=true;dec(numb);
             end;
          inc(j);
       end;
   if numb = n-1 then
      begin
         writeln;
         for i:=1 to numb do
         begin
            write('(',Tree[1,i],' ',Tree[2,i],')');
            if Tree[2, i]<>Tree[1, i+1] then
            writeln;
            end;
         exit;
      end;
   if j = n+1 then
      begin
         inc(d);
         solve(Turn[d],1);
         dec(d);
      end;
end;

begin
clrscr;
assign(inp, 'Graph.dat');
assign(outp, 'Graph.sol');
reset(inp);
rewrite(outp);
   readln(n);
   for i:=1 to n do
      for j:=1 to n do
         read(a[i,j]);
   fillchar(Nnew,sizeof(Nnew),true);
   fillchar(Tree,sizeof(Tree),0);
   Nnew[1]:=false;
   Turn[1]:=1;d:=1;u:=2;numb:=0;
   solve(1,2);
close(inp);
close(outp);

end.