import sys

sys.setrecursionlimit(10**7)
def I(): return int(sys.stdin.readline().rstrip())
def MI(): return map(int,sys.stdin.readline().rstrip().split())
def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))
def LI2(): return list(map(int,sys.stdin.readline().rstrip()))
def S(): return sys.stdin.readline().rstrip()
def LS(): return list(sys.stdin.readline().rstrip().split())
def LS2(): return list(sys.stdin.readline().rstrip())


def matrix_multiplication(A,B):
    l = len(A)
    m = len(B)
    n = len(B[0])
    C = [[0]*n for _ in range(l)]
    for i in range(l):
        for j in range(n):
            for k in range(m):
                C[i][j] |= A[i][k] & B[k][j]
    return C


def matrix_power(A,n):
    l = len(A)
    C = [[0]*l for _ in range(l)]
    for i in range(l):
        C[i][i] = 1
    while n > 0:
        if n % 2 == 1:
            C = matrix_multiplication(C,A)
        A = matrix_multiplication(A,A)
        n >>= 1
    return C


N,M,T = MI()
Graph = [[0]*N for _ in range(N)]
for _ in range(M):
    a,b = MI()
    Graph[a][b] = 1

X = matrix_power(Graph,T)
initial_state = [[1]]+[[0]]*(N-1)

ANS = matrix_multiplication(X,initial_state)
ans = 0
for i in range(N):
    ans += ANS[i][0]

print(ans)