import sys
input = sys.stdin.readline

N,M,T=map(int,input().split())

mod=1+(1<<30)

# 行列の計算（numpyを使えないとき,modを使用）
def prod(A,B,k,l,m):# A:k*l,B:l*m
    C=[[None for i in range(m)] for j in range(k)]

    for i in range(k):
        for j in range(m):
            ANS=0
            for pl in range(l):
                ANS=(ANS+A[i][pl]*B[pl][j])%mod

            C[i][j]=ANS

    return C

def plus(A,B,k,l):# a,B:k*l
    C=[[None for i in range(l)] for j in range(k)]

    for i in range(k):
        for j in range(l):
            C[i][j]=(A[i][j]+B[i][j])%mod

    return C

A=[[0]*N for i in range(N)]

for i in range(M):
    a,b=map(int,input().split())
    A[a][b]=1

# 漸化式を行列累乗で求める（ダブリング）

POWA=[A]

for i in range(60):
    POWA.append(prod(POWA[-1],POWA[-1],N,N,N)) # ベキを求めて


X=[[0]*N]
X[0][0]=1
#print(X)
while T:
    X=prod(X,POWA[T.bit_length()-1],1,N,N) # n乗の場合
    T-=1<<(T.bit_length()-1)

#print(X)

ANS=0
for i in X[0]:
    if i>0:
        ANS+=1

print(ANS)