N,M,T = map(int,input().split())
R = [[0] * N for _ in range(N)]
for _ in range(M):
    s,t = map(int,input().split())
    R[s][t] = 1
    R[t][s] = 1
P = 998244353
def seki(x,y):
    l = [[0] * N for _ in range(N)]
    for i in range(N):
        for j in range(N):
            for k in range(N):
                l[i][j] = (l[i][j] + x[i][k] * y[k][j]) % P
    return l
e = [[0] * N for _ in range(N)]
for i in range(N):
    e[i][i] = 1
while T:
    if T & 1:
        e = seki(e,R)
    R = seki(R,R)
    T >>= 1
print(e[0][0])