def matmul(A,B): # A,B: 行列
    n = len(A)
    res = [[0]*n for _ in range(n)]
    for i in range(n):
        for k in range(n):
            for j in range(n):
                res[i][j] |= A[i][k]&B[k][j]
    return res

def matpow(A,p): #A^p mod M
    if p%2:
        return matmul(A, matpow(A,p-1))
    elif p > 0:
        b = matpow(A,p//2)
        return matmul(b,b)
    else:
        return [[1 if i == j else 0 for j in range(len(A))] for i in range(len(A))]

n,m,t,*ab = map(int,open(0).read().split())
g = [[0]*n for _ in range(n)]
for i in range(m):
    g[ab[i*2]][ab[i*2+1]]=1
A = matpow(g,t)
print(sum(A[0]))