def multiply(a, b):
    n = len(a)
    res = [[False] * n for _ in range(n)]
    for i in range(n):
        for k in range(n):
            if a[i][k]:
                for j in range(n):
                    if b[k][j]:
                        res[i][j] = True
    return res

def matrix_pow(mat, power):
    n = len(mat)
    result = [[False] * n for _ in range(n)]
    for i in range(n):
        result[i][i] = True  # Identity matrix
    current = [row[:] for row in mat]
    while power > 0:
        if power % 2 == 1:
            result = multiply(result, current)
        current = multiply(current, current)
        power = power // 2
    return result

def main():
    import sys
    input = sys.stdin.read().split()
    idx = 0
    n = int(input[idx])
    idx += 1
    m = int(input[idx])
    idx += 1
    T = int(input[idx])
    idx += 1

    edges = [[] for _ in range(n)]
    for _ in range(m):
        a = int(input[idx])
        idx += 1
        b = int(input[idx])
        idx += 1
        edges[a].append(b)

    out_degree = [len(edges[i]) for i in range(n)]

    mat = [[False] * n for _ in range(n)]
    for i in range(n):
        if out_degree[i] >= 1:
            for j in edges[i]:
                mat[i][j] = True

    if T == 0:
        print(1)
        return

    mt = matrix_pow(mat, T)

    count = sum(mt[0][j] for j in range(n))
    print(count)

if __name__ == "__main__":
    main()