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

"""行列累乗を https://qiita.com/ophhdn/items/e6451ec5983939ecbc5b から拝借しています"""


def mat_mul(a, b):
    I, J, K = len(a), len(b[0]), len(b)
    c = [[0] * J for _ in range(I)]
    for i in range(I):
        for j in range(J):
            for k in range(K):
                c[i][j] += a[i][k] * b[k][j]
            c[i][j] %= MOD
    return c


def mat_pow(x, n):
    y = [[0] * len(x) for _ in range(len(x))]

    for i in range(len(x)):
        y[i][i] = 1

    while n > 0:
        if n & 1:
            y = mat_mul(x, y)
        x = mat_mul(x, x)
        n >>= 1

    return y


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

print(mat_pow(matr, T)[0][0])