import sys
input = sys.stdin.buffer.readline

# 行列の乗算(mod)
def mat_mul(a, b):
	I, K, J = len(a), len(b), len(b[0])
	c = [[0 for j in range(J)] for i in range(I)]
	for i in range(I):
		for k in range(K):
			for j in range(J):
				c[i][j] += a[i][k] * b[k][j]
				c[i][j] %= mod
	return c

# 行列の累乗(mod)
def mat_pow(a, n):
	b = [[0 for j in range(len(a))] for i in range(len(a))]
	for i in range(len(a)):
		b[i][i] = 1
	while n > 0:
		if n & 1:
			b = mat_mul(b, a)
		a = mat_mul(a, a)
		n >>= 1
	return b


n,m,T = map(int,input().split())
mod = 998244353

st = [[0]*n for i in range(n)]

for i in range(m):
    s,t = map(int,input().split())
    st[s][t] = 1
    st[t][s] = 1

A = mat_pow(st,T)

print(A[0][0])