from collections import defaultdict
import numpy as np

N, M, T = map(int, input().split())
A = np.zeros(shape=(N, N), dtype=np.int64)
for _ in range(M):
    s, t = map(int, input().split())
    A[s, t] = 1
    A[t, s] = 1


mod = 998244353

def mat_mul(A, B, MOD):
    A1, A2 = A >> 15, A & (1 << 15) - 1
    B1, B2 = B >> 15, B & (1 << 15) - 1
    AB1 = np.dot(A1, B1) % MOD
    AB2 = np.dot(A2, B2)
    AB3 = np.dot(A1+A2, B1+B2) - AB1 - AB2
    return ((AB1 << 30) + (AB3 << 15) + AB2) % MOD


def mat_pow(A, K):
    P = np.eye(len(A), dtype=np.int64)
    while K:
        if K & 1:
            P = mat_mul(A, P, mod)
        A = mat_mul(A, A, mod)
        K >>= 1
    return P

P = mat_pow(A, T)
print(P[0, 0])