import sys
input = sys.stdin.readline

N,M,T=map(int,input().split())
mod=998244353

X=[[0]*N for i in range(N)]
for i in range(M):
    s,t=map(int,input().split())
    X[s][t]=X[t][s]=1
    
# 行列の計算（numpyを使えないとき,modを使用）
def prod(A,B,k,l,m):# A:k*l,B:l*m
    C=[[None for i in range(m)] for j in range(k)]

    for i in range(k):
        for j in range(m):
            ANS=0
            for pl in range(l):
                ANS=(ANS+A[i][pl]*B[pl][j])%mod

            C[i][j]=ANS

    return C

def plus(A,B,k,l):# a,B:k*l
    C=[[None for i in range(l)] for j in range(k)]

    for i in range(k):
        for j in range(l):
            C[i][j]=(A[i][j]+B[i][j])%mod

    return C

# 漸化式を行列累乗で求める（ダブリング）

POWA=[X]

for i in range(60):
    POWA.append(prod(POWA[-1],POWA[-1],N,N,N)) # ベキを求めて

n=T
X=[0]*N
X[0]=1
X=[X]
while n:
    X=prod(X,POWA[n.bit_length()-1],1,N,N) # n乗の場合
    n-=1<<(n.bit_length()-1)

print(X[0][0])