#include <algorithm>
#include <iomanip>
#include <array>
#include <bitset>
#include <cassert>
#include <cmath>
#include <cstdio>
#include <deque>
#include <functional>
#include <iostream>
#include <iterator>
#include <map>
#include <queue>
#include <set>
#include <string>
#include <sstream>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <numeric>
#include <vector>
#include <climits>
using namespace std;
#if __has_include(<atcoder/all>)
#include <atcoder/all>
using namespace atcoder;
#endif
#define GET_MACRO(_1, _2, _3, NAME, ...) NAME
#define _rep(i, n) _rep2(i, 0, n)
#define _rep2(i, a, b) for(int i = (int)(a); i < (int)(b); i++)
#define rep(...) GET_MACRO(__VA_ARGS__, _rep2, _rep)(__VA_ARGS__)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
using i64 = long long;
template<class T, class U>
bool chmin(T& a, const U& b) { return (b < a) ? (a = b, true) : false; }
template<class T, class U>
bool chmax(T& a, const U& b) { return (b > a) ? (a = b, true) : false; }

template<typename T>istream& operator>>(istream&i,vector<T>&v){rep(j,v.size())i>>v[j];return i;}
template<typename T>string join(vector<T>&v){stringstream s;rep(i,v.size())s<<' '<<v[i];return s.str().substr(1);}
template<typename T>ostream& operator<<(ostream&o,vector<T>&v){if(v.size())o<<join(v);return o;}
template<typename T>string join(vector<vector<T>>&vv){string s="\n";rep(i,vv.size())s+=join(vv[i])+"\n";return s;}
template<typename T>ostream& operator<<(ostream&o,vector<vector<T>>&vv){if(vv.size())o<<join(vv);return o;}
template<class T> using pq = priority_queue<T, vector<T>, greater<T>>;

// 行列積
template<class T>
vector<vector<T>> operator*(vector<vector<T>>& a, vector<vector<T>>& b)
{
    vector res(a.size(), vector<T>(b[0].size(), 0));
    rep(i, res.size()) rep(j, res[0].size()) rep(k, a[0].size())
    {
        res[i][j] += a[i][k] * b[k][j];
    }
    return res;
}

// 行列累乗
template<class T>
vector<vector<T>> mat_pow(vector<vector<T>> a, long long n)
{
    vector res(a.size(), vector<T>(a.size()));
    rep(i, a.size()) res[i][i] = 1;
    while(n)
    {
        if(n & 1) res = res * a;
        a = a * a;
        n >>= 1;
    }
    return res;
}

using mint = modint998244353;

int main() {
    int n, m;
    i64 T;
    cin >> n >> m >> T;

    vector matrix(n, vector<mint>(n));

    rep(_, m) {
        int s, t;
        cin >> s >> t;
        matrix[s][t] = matrix[t][s] = 1;
    }

    cout << mat_pow(matrix, T)[0][0].val() << endl;

    return 0;
}