#pragma GCC target("avx")
#pragma GCC optimize("O2")
#pragma GCC optimize("unroll-loops")

#include <bits/stdc++.h>
using namespace std;

const int MOD = 998244353;

int N, M;
long long T;

vector<vector<long long>> mul(const vector<vector<long long>> &A, const vector<vector<long long>> &B) {
    vector<vector<long long>> ret(N, vector<long long>(N, 0));
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            for (int k = 0; k < N; k++) {
                ret[i][j] += A[i][k] * B[k][j];
                ret[i][j] %= MOD;
            }
        }
    }

    return ret;
}

int main() {
    cin >> N >> M >> T;
    vector<vector<long long>> mat(N, vector<long long>(N, 0));
    for (int i = 0; i < M; i++) {
        int s, t;
        cin >> s >> t;
        mat[s][t] = mat[t][s] = 1;
    }

    vector<vector<long long>> A(N, vector<long long>(N, 0));
    for (int i = 0; i < N; i++) A[i][i] = 1;

    while (T > 0) {
        if (T & 1) {
            A = mul(A, mat);
        }
        mat = mul(mat, mat);
        T >>= 1;
    }

    cout << A[0][0] << endl;
}