program Project2;

{$APPTYPE CONSOLE}

uses
  SysUtils;
var
  i, l, r, n, s, f, j, sum : integer;
  arr : array[1..100,1..100]of integer;
  used : array [1..100] of boolean;
  q : array [1..100] of integer;
  otvet : array[1..100] of integer;
begin
  reset(input,'bfs.in');
  rewrite(output,'bfs.out');
  read(n,s,f);
  for i := 1 to n do
    begin
      for j := 1 to n do
        begin
          read(arr[i,j]);
        end;
    end;
  for i:=1 to n do
    begin
      used[i]:=false;
    end;
  l:=1;
  r:=1;
  q[r]:=s;
  sum:=1;
  otvet[s] := 0;
  used[s]:=true;
  while l <= r do
    begin
      for i := 1 to n do
        begin
          if (arr[s,i]=1) and (not used[i]) then
            begin
              inc(r);
              q[r] := i;
              used[i] := TRUE;
              otvet[i] := sum;
            end;
        end;
      inc(l);
      s := q[r];
      inc(sum);
    end;
  write(otvet[f]);
  readln;
  readln;
end.