n, m, t = map(int, input().split())
edges = [[] for _ in range(n)]
for _ in range(m):
    a, b = map(int, input().split())
    edges[a].append(b)

if t == 0:
    print(1)
else:
    # Construct the transition matrix masks
    mask = []
    for i in range(n):
        if not edges[i]:
            mask.append(0)
        else:
            m_val = 0
            for j in edges[i]:
                m_val |= 1 << j
            mask.append(m_val)

    def multiply(a, b):
        n_mat = len(a)
        result = [0] * n_mat
        for i in range(n_mat):
            row = a[i]
            res = 0
            k = 0
            while row > 0 and k < n_mat:
                if row & 1:
                    res |= b[k]
                row >>= 1
                k += 1
            result[i] = res
        return result

    def matrix_power(mat, power):
        n_mat = len(mat)
        # Initialize result as identity matrix
        result = [0] * n_mat
        for i in range(n_mat):
            result[i] = 1 << i
        while power > 0:
            if power % 2 == 1:
                result = multiply(result, mat)
            mat = multiply(mat, mat)
            power //= 2
        return result

    mt = matrix_power(mask, t)
    res_mask = mt[0]
    print(bin(res_mask).count('1'))