import sys
input = sys.stdin.buffer.readline
sys.setrecursionlimit(10 ** 7)
mod = 998244353


def mat_mul(A, B):
    res = [[0] * len(B[0]) for _ in range(len(A))]
    for i in range(len(A)):
        for k in range(len(A[0])):
            for j in range(len(B[0])):
                res[i][j] += A[i][k] * B[k][j]
                res[i][j] %= mod
    return res


def mat_pow(A, n):
    size = len(A)
    res = [[0] * size for _ in range(size)]
    for i in range(size):
        res[i][i] = 1
    while n:
        if n & 1:
            res = mat_mul(res, A)
        A = mat_mul(A, A)
        n >>= 1
    return res


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

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