#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define rep(i,n) for(int i=0;i<n;i++)
#define rrep(i,n) for(int i=n-1;i>=0;i--)
#define rrep2(i,n,k) for(int i=n-1;i>=n-k;i--)
#define vll(n,i) vector<long long>(n,i)
#define v2ll(n,m,i) vector<vector<long long>>(n,vll(m,i))
#define v3ll(n,m,k,i) vector<vector<vector<long long>>>(n,v2ll(m,k,i))
#define v4ll(n,m,k,l,i) vector<vector<vector<vector<long long>>>>(n,v3ll(m,k,l,i))
#define all(v) v.begin(),v.end()
#define chmin(k,m) k = min(k,m)
#define chmax(k,m) k = max(k,m)
#define Pr pair<ll,ll>
#define Tp tuple<int,int,int>
#define riano_ std::ios::sync_with_stdio(false);std::cin.tie(nullptr)
using Graph = vector<vector<int>>;

const ll mod = 998244353;
template<uint64_t mod>
struct modint{
    uint64_t val;
    constexpr modint(const int64_t val_=0) noexcept:val((val_%int64_t(mod)+int64_t(mod))%int64_t(mod)){}
    constexpr modint operator-() const noexcept{
        return modint(*this)=mod-val;
    }
    constexpr modint operator+(const modint rhs) const noexcept{
        return modint(*this)+=rhs;
    }
    constexpr modint operator-(const modint rhs) const noexcept{
        return modint(*this)-=rhs;
    }
    constexpr modint operator*(const modint rhs) const noexcept{
        return modint(*this)*=rhs;
    }
    constexpr modint operator/(const modint rhs) const noexcept{
        return modint(*this)/=rhs;
    }
    constexpr modint &operator+=(const modint rhs) noexcept{
        val+=rhs.val;
        val-=((val>=mod)?mod:0);
        return (*this);
    }
    constexpr modint &operator-=(const modint rhs) noexcept{
        val+=((val<rhs.val)?mod:0);
        val-=rhs.val;
        return (*this);
    }
    constexpr modint &operator*=(const modint rhs) noexcept{
        val=val*rhs.val%mod;
        return (*this);
    }
    constexpr modint &operator/=(modint rhs) noexcept{
        uint64_t ex=mod-2;
        modint now=1;
        while(ex){
            now*=((ex&1)?rhs:1);
            rhs*=rhs,ex>>=1;
        }
        return (*this)*=now;
    }
    modint & operator++(){
        val++;
        if (val == mod) val = 0;
        return *this;
    }
    modint operator++(int){
        modint<mod> res = *this;
        ++*this;
        return res;
    }
    constexpr bool operator==(const modint rhs) noexcept{
        return val==rhs.val;
    }
    constexpr bool operator!=(const modint rhs) noexcept{
        return val!=rhs.val;
    }
    friend constexpr ostream &operator<<(ostream& os,const modint x) noexcept{
        return os<<(x.val);
    }
    friend constexpr istream &operator>>(istream& is,modint& x) noexcept{
        uint64_t t;
        is>>t,x=t;
        return is;
    }
};
typedef modint<mod> mint;
#define vm(n,i) vector<mint>(n,i)
#define v2m(n,m,i) vector<vector<mint>>(n,vm(m,i))
#define v3m(n,m,k,i) vector<vector<vector<mint>>>(n,v2m(m,k,i))
#define v4m(n,m,k,l,i) vector<vector<vector<vector<mint>>>>(n,v3m(m,k,l,i))


//行列累乗 matrix power
//modをglobalに定義しておく
vector<vector<ll>> pw_matrix(vector<vector<ll>> &M,ll n){
    if(n==0){
        vector<vector<ll>> E = M;
        rep(i,M.size()){
            rep(j,M.size()){
                if(i==j) E[i][j] = 1;
                else E[i][j] = 0;
            }
        }
        return E;
    }
    if(n==1) return M;
    if(n%2==1){
        auto K = pw_matrix(M,n-1);
        int a = M.size();
        vector<vector<ll>> L(a,vector<ll>(a));
        rep(i,a){
            rep(j,a){
                ll b = 0;
                rep(k,a) b += (M[i][k]*K[k][j])%mod;
                L[i][j] = b%mod;
            }
        }
        return L;
    }
    if(n%2==0){
        auto K = pw_matrix(M,n/2);
        int a = M.size();
        vector<vector<ll>> L(a,vector<ll>(a));
        rep(i,a){
            rep(j,a){
                ll b = 0;
                rep(k,a) b += (K[i][k]*K[k][j])%mod;
                L[i][j] = b%mod;
            }
        }
        return L;
    }
}

    
int main() {
    riano_; ll ans = 0;
    ll N,M,T; cin >> N >> M >> T;
    
    //main関数内 sizeは適宜買える
    vector<vector<ll>> Mat(N,vector<ll>(N,0)); //もとの行列
    rep(i,M){
        ll s,t; cin >> s >> t;
        Mat[s][t] = 1; Mat[t][s] = 1;
    }

    vector<ll> a(N,0); //初期値
    a[0] = 1;
    //行列の成分を代入
    
    auto S = pw_matrix(Mat,T);
    
    rep(i,3){ //size変える
        ans += (S[0][i]*a[i])%mod;
        ans %= mod;
    }


    cout << ans << endl;
}