def mul(a, b, mod=998244353):
    n = len(a)
    ans = [[0]*n for i in range(n)]
    for i in range(n):
        for j in range(n):
            for k in range(n):
                ans[i][j] += a[i][k] * b[k][j]
                ans[i][j] %= mod
    return ans


n, m, t = map(int, input().split())
mod = 998244353
graph = [[0]*n for i in range(n)]
for i in range(m):
    a, b = map(int, input().split())
    graph[a][b] = 1
    graph[b][a] = 1

ans = [[0]*n for i in range(n)]
for i in range(n):
    ans[i][i] = 1

t_bin = bin(t)[2:]
for i in range(len(t_bin))[::-1]:
    if t_bin[i] == "1":
        ans = mul(graph, ans)
    graph = mul(graph, graph)

print(ans[0][0])