n, m, t = map(int, input().split())
A = [[0]*n for i in range(n)]
for i in range(m):
    a, b = map(int, input().split())
    A[b][a] = 1
#print(A)
mod = 10**9+7
# A*B
def mat_mul(A, B, mod):
    C = [[0]*len(B[0]) for i in range(len(A))]
    for i in range(len(A)):
        for k in range(len(B)):
            for j in range(len(B[0])):
                C[i][j] = (C[i][j] + A[i][k]*B[k][j])%mod
    return C

#A**n
def mat_pow(A, n, mod):
    B = [[0]*len(A) for i in range(len(A))]
    for i in range(len(A)):
        B[i][i] = 1
    while n > 0:
        if n & 1 == 1:
            B = mat_mul(A, B, mod)
        A = mat_mul(A, A, mod)
        n = n>>1
    return B

X = [0]*n
X[0] = 1
A = mat_pow(A, t, mod)
ans = 0
for i in range(n):
    s = 0
    for j in range(n):
        s += A[i][j]*X[j]
    if s:
        ans += 1
#print(A)
print(ans)