import numpy as np

n, m, t = map(int, input().split())
mod = 998244353
graph = np.zeros([n, n], dtype="int64")
for i in range(m):
    a, b = map(int, input().split())
    graph[a][b] = 1
    graph[b][a] = 1

ans = np.identity(n, dtype="int64")
t_bin = bin(t)[2:]
for i in range(t.bit_length())[::-1]:
    if t_bin[i] == "1":
        ans = graph @ ans
        ans %= mod
    graph = graph @ graph
    graph %= mod
    
b = np.zeros([n, 1], dtype="int64")
b[0][0] = 1
print((ans @ b)[0][0])