def Matprod(A, B, mod):
    N = len(A)
    temp = [[0] * N for i in range(N)]
    for i in range(N):
        for j in range(N):
            for k in range(N):
                temp[i][j] += A[i][k] * B[k][j]
                temp[i][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][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 for i in range(N)]
for i in range(M):
    s, t = map(int, input().split())
    G[s][t] = 1
    G[t][s] = 1

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