public static void Main()
{
Console.SetOut(new StreamWriter(Console.OpenStandardOutput())
{
AutoFlush = false
});
var n = NextInt;
var q = NextInt;
var uf = new PotentializedUnionFind <int>(n, (x, y) => x + y, x => - x, 0);
for (int i = 0; i < q; i++)
{
if (NextInt == 0)
{
uf.TryUnite(NextInt, NextInt, NextInt);
}
else
{
var a = NextInt;
var b = NextInt;
Console.WriteLine(uf.Find(a) == uf.Find(b) ? uf.GetPotential(b, a).ToString() : "?");
}
}
Console.Out.Flush();
}
public static void Main()
{
int n = int.Parse(Console.ReadLine());
int[][] matrix = Enumerable.Range(0, n).Select(h => Console.ReadLine().Select((x, w) => h == w ? 0 : x == '1' ? 1 : 1 << 29).ToArray()).ToArray();
PotentializedUnionFind <bool> puf = new PotentializedUnionFind <bool>(n, (x, y) => x ^ y, x => x, false);
for (int i = 0; i < n; i++)
{
for (int j = 0; j < n; j++)
{
if (matrix[i][j] == 1 && !puf.TryUnite(i, j, true))
{
Console.WriteLine(-1);
return;
}
}
}
for (int i = 0; i < n; i++)
{
for (int j = 0; j < n; j++)
{
for (int k = 0; k < n; k++)
{
matrix[j][k] = Min(matrix[j][k], matrix[j][i] + matrix[i][k]);
}
}
}
Console.WriteLine(matrix.Max(x => x.Max()) + 1);
}
