N, M, T = map(int, input().split())
AB = [list(map(int, input().split())) for _ in range(M)]
A = [[0] * N for _ in range(N)]
for a, b in AB:
    A[b][a] = 1
D = N

def mt(A, B):
    C = [[0] * D for _ in range(D)]
    for i in range(D):
        for j in range(D):
            tmp = 0
            for k in range(D):
                tmp |= A[i][k] * B[k][j]
            C[i][j] = tmp
    return C

X = [[0] * N for _ in range(N)]
for i in range(N):
    X[i][i] = 1

while T > 0:
    if T & 1:
        X = mt(A, X)
    A = mt(A, A)
    T >>= 1
ans = 0
for i in range(N):
    ans += X[0][i]
print(ans)