import numpy as np

N, M, T = map(int, input().split())
MOD = 998244353


def pow_matrix_mod(x, n, mod=MOD):
    if not n:
        return np.eye(len(x), dtype=object)
    if n % 2 == 0:
        return pow_matrix_mod(x @ x % mod, n // 2) % mod
    else:
        return x @ pow_matrix_mod(x @ x % mod, (n - 1) // 2) % mod


matr = [[0] * N for _ in range(N)]
for _ in range(M):
    s, t = map(int, input().split())
    matr[s][t] = 1
    matr[t][s] = 1

matr = np.array(matr, dtype=object)
print(pow_matrix_mod(matr, T)[0, 0])