import numpy as np
MOD = 998244353
 
 
def mult(N, A, B):
    C = np.zeros((N, N), np.int64)
    for n in range(N):
        C[n] = (A[n, :][:, None] * B % MOD).sum(axis=0) % MOD
    return C
 
 
def mat_power(A, N, k):
    if k == 0:
        return np.eye(N, dtype=np.int64)
    X = mat_power(A, N, k//2)
    X = mult(N, X, X)
    return mult(N, A, X) if k & 1 else X
 
 
n, m, tt = map(int, input().split())
a = np.zeros((n, n), np.int64)
for i in range(m):
    s, t = map(int, input().split())
    a[s][t] = 1
    a[t][s] = 1
print(mat_power(a, n, tt)[0][0] % MOD)