uses crt;
var a:array[1..100]of integer;
i,n:integer;
begin
clrscr;
readln(n);
for i:=1 to n do
readln(a[i]);
for i:=1 to n do
write(a[i]:4);
writeln;
for i:=1 to n do
if (a[i]+a[i+1] mod 10=0) then
begin
writeln(a[i],' ',a[i+1]);
writeln(i,' ',i+1);
end;
readln;
end.