import scala.annotation.tailrec
import scala.io.StdIn.*
import scala.math.*
import scala.util.chaining.*

object ModInt:
  opaque type ModInt = Long
  val zero: ModInt = 0
  val one: ModInt = 1
  extension (value: Long)
    inline def asModInt(using inline mod: Int): ModInt =  value % mod
  extension (value: Int)
    inline def asModInt(using inline mod: Int): ModInt = value % mod
  trait Converter[T]:
    inline def convert(value: T)(using inline mod: Int): ModInt
  inline given Converter[Int] with
    override inline def convert(value: Int)(using inline mod: Int) = value.asModInt
  inline given Converter[Long] with
    override inline def convert(value: Long)(using inline mod: Int) = value.asModInt
  inline given Converter[ModInt] with
    override inline def convert(value: ModInt)(using inline mod: Int) = value
  extension (modInt: ModInt)
    inline def asLong(using inline mod: Int): Long = (modInt + mod) % mod
    inline def inverse(using inline mod: Int): ModInt = modInt.powMod(mod - 2)
    inline def powMod(exp: Long)(using inline mod: Int): ModInt =
      var result = 1L
      var base = modInt
      var e = exp
      while e > 0 do
        if (e & 1) == 1 then
          result = result * base % mod
        base = base * base % mod
        e >>= 1
      result
    inline def powMod(exp: Int)(using inline mod: Int): ModInt = powMod(exp.toLong)
  extension [L: Converter, R: Converter] (left: L)
    inline def +(right: R)(using inline mod: Int): ModInt = (summon[Converter[L]].convert(left) + summon[Converter[R]].convert(right)).asModInt
    inline def -(right: R)(using inline mod: Int): ModInt = (summon[Converter[L]].convert(left) - summon[Converter[R]].convert(right)).asModInt
    inline def *(right: R)(using inline mod: Int): ModInt = (summon[Converter[L]].convert(left) * summon[Converter[R]].convert(right)).asModInt
    inline def /(right: R)(using inline mod: Int): ModInt = (summon[Converter[L]].convert(left) * summon[Converter[R]].convert(right).inverse).asModInt

import ModInt.*
inline given mod: Int = 998244353
class Matrix private(val row: Int, val column: Int, private val matrix: Array[Array[ModInt]]):
  def this(row: Int, column: Int) =
    this(row, column, Array.fill(row){Array.fill(column){ModInt.zero}})
  def apply(i: Int, j: Int): ModInt =
    matrix(i)(j)
  def update(i: Int, j: Int, value: ModInt) =
    matrix(i)(j) = value
  def *(right: Matrix): Matrix =
    val newRow = row
    val newColumn = right.column
    val mid = column
    Matrix.tabulate(newRow, newColumn){(i, j) =>
      (0 until mid).foldLeft(ModInt.zero){(acc, k) => acc + matrix(i)(k) * right.matrix(k)(j) }
    }
  def pow(exp: Long): Matrix =
    require(row == column)
    var result = Matrix.e(row, row)
    var base = this
    var e = exp
    while e > 0 do
      if (e & 1) == 1 then
        result *= base
      base *= base
      e >>= 1
    result
object Matrix:
  def tabulate(row: Int, column: Int)(generator: (Int, Int) => ModInt): Matrix =
    Matrix(row, column, Array.tabulate(row){i => Array.tabulate(column){j => generator(i, j)}})
  def e(row: Int, column: Int): Matrix =
    Matrix.tabulate(row, column){(i, j) =>
      if i == j then ModInt.one else ModInt.zero
    }


@main def main =
  val (n, m, t) = readLine().split(' ').pipe{case Array(n, m, t) => (n.toInt, m.toInt, t.toLong)}
  val roads = Array.fill(m){
    val Array(u, v) = readLine().split(' ').map(_.toInt)
    (u, v)
  }
  val matrix = Matrix(n, n)
  for (u, v) <- roads do
    matrix(u, v) = ModInt.one
    matrix(v, u) = ModInt.one
  val initial = Matrix(n, 1).tap(m => m(0, 0) = ModInt.one)
  val result = matrix.pow(t) * initial
  println(result(0, 0))