def oi(): return int(input())
def os(): return input()
def mi(): return list(map(int, input().split()))

# import sys
# input = sys.stdin.readline
# import sys
# sys.setrecursionlimit(10**8)
# import pypyjit
# pypyjit.set_param('max_unroll_recursion=-1')
input_count = 0

def prod_func(a,b):
    return a*b
def add_func(a,b):
    return a+b

class MATRIX:
    def __init__(self, prod_func, add_func):
        self.prod_func = prod_func
        self.add_func = add_func
        
    def dot(self, A,B):
        if len(A[0]) != len(B):
            return None
        out = []
        for ay in range(len(A)):
            temp = []
            for bx in range(len(B[0])):
                sums = 0
                for ax in range(len(A[0])):
                    sums += self.prod_func(A[ay][ax], B[ax][bx])
                temp.append(sums)
            out.append(temp)
        return out

    def sum(self, A,B):
        if not(len(A) == len(B) and len(A[0]) == len(B[0])):
            return None
        out = []
        for ay in range(len(A)):
            temp = []
            for ax in range(len(A[0])):
                temp.append(self.add_func(A[ay][ax], B[ay][ax]))
            out.append(temp)
        return out

    def prod(self, A,B):
        if not(len(A) == len(B) and len(A[0]) == len(B[0])):
            return None
        out = []
        for ay in range(len(A)):
            temp = []
            for ax in range(len(A[0])):
                temp.append(self.prod_func(A[ay][ax], B[ay][ax]))
            out.append(temp)
        return out

    # 正方行列AをN乗する。
    def ruijou(self, A, N):
        out = [[0] * len(A) for _ in range(len(A))]
        for i in range(len(A)):
            out[i][i] = 1

        for i in list(bin(N)[2:][::-1]):
            if i=="1":
                out = self.dot(out, A)
            A = self.dot(A,A)
        return out

input_count = 0
N,M,T = mi()
mat = [[0] * N for _ in range(N)]
MAT = MATRIX(prod_func, add_func)
for i in range(M):
    a,b = mi()
    mat[a][b] = 1
out = MAT.ruijou(mat, T)
count = 0
for o in out[0]:
    if o>0:
        count += 1
print(count)