def Matprod(A, B, mod):
    N = len(A)
    temp = [0] * (N * N)
    for i in range(N):
        for k in range(N):
            for j in range(N):
                temp[i*N+j] += A[i*N+k] * B[k*N+j]
                temp[i*N+j] %= mod
    return temp

def Matpow(A, M, mod):
    N = len(A)
    Mat = [[0] * N for i in range(N)]
    for i in range(N):
        Mat[i*N+i] = 1
         
    for i in range(64):
        if (M >> i) & 1:
            Mat = Matprod(Mat, A, mod)
        A = Matprod(A, A, mod)
    return Mat

N, M, T = map(int, input().split())
mod = 998244353
G = [0] * (N * N)
for i in range(M):
    s, t = map(int, input().split())
    G[s*N+t] = 1
    G[t*N+s] = 1

G = Matpow(G, T, mod)
print(G[0])