N,M,T = map(int, input().split())
MOD = 998244353
MAP = [[0] * N for _ in range(N)]
for i in range(M):
    a,b = map(int, input().split())
    MAP[a][b]=1
    MAP[b][a]=1
R = [[0] * N for _ in range(N)]
R[0][0]=1

def exp(mat_a, mat_b):
    new_mat = [[0]*N for _ in range(N)]
    for i in range(N):
        for j in range(N):
            new_mat[i][j] = sum(mat_a[i][w]*mat_b[w][j] % MOD for w in range(N)) % MOD
    return new_mat

while T:
    if T & 1:
        R = exp(R, MAP)
    MAP = exp(MAP, MAP)
    T //= 2

print(R[0][0])