#include<bits/stdc++.h>
#include<atcoder/all>
using namespace atcoder;
template<typename V>struct ve;
using ml=modint;using m1=ve<ml>;
auto&operator>>(std::istream&i,ml&x){long long t;i>>t;x=t;return i;}
auto&operator<<(std::ostream&o,const ml&x){return o<<x.val();}
#define eb(...) emplace_back(__VA_ARGS__)
#define all(a) begin(a),end(a)
#define eif(...) else if(__VA_ARGS__)
#define RD(T,...) T __VA_ARGS__;li(__VA_ARGS__)
#define LL(...) RD(ll,__VA_ARGS__)
#define JO(a,b) a##b
#define jo(a,b) JO(a,b)
#define FE(v,e,...) for(au&&__VA_OPT__([)e __VA_OPT__(,__VA_ARGS__]):v)
#define FO(n) for(ll jo(i,____LINE__)=n;jo(i,____LINE__)-->0;)
#define FOR(i,...) for(au[i,i##O,i##E]=rng(0,__VA_ARGS__);i<i##O;i+=i##E)
#define fe(v,...) FE(v,__VA_ARGS__)
#define fo(i,...) FO##__VA_OPT__(R)(i __VA_OPT__(,__VA_ARGS__))
#define I(...) template<__VA_ARGS__>
#define J typename
#define O operator
#define au auto
#define cs const
#define ifc if constexpr
#define rr return
#define uu using
uu std::cin,std::cout,std::begin,std::end,std::rbegin,std::get;
uu std::swap,std::move,std::abs,std::prev,std::next;
uu std::tuple,std::array,std::bitset,std::minmax;
uu vo=void;uu bo=bool;
vo solve();
I(J A,J B)constexpr bo same=std::is_same_v<A,B>;
I(bo b,J A,J B)uu ift=std::conditional_t<b,A,B>;
uu is=std::istream;uu os=std::ostream;
uu dd=long double;uu ll=long long;uu ull=unsigned long long;
uu lll=__int128_t;uu ulll=__uint128_t;uu str=std::string;
dd ee=1e-12;
ll oo=3e18;
array<ll,8>dx{-1,0,1,0,-1,1,1,-1},dy{0,-1,0,1,-1,-1,1,1};
char sp=32;
char nl=10;
I(J T,ll n)au TP(){ifc(n)rr tuple_cat(tuple(T()),TP<T,n-1>());else rr tuple();}
I(J T,ll n)uu tp=decltype(TP<T,n>());I(ll n)uu tpl=tp<ll,n>;
au rng(bo s,ll a,ll b=oo,ll c=1){if(b==oo)b=a,a=0;rr tuple{a,b-s,c};}

I(J T)T zz(T x){rr x<0?-x:x;}
I(J T)ll len(cs T&a){rr a.size();}
I(J...A)au max(cs A&...a){rr max(std::initializer_list<std::common_type_t<A...>>{a...});}

struct edg{
  ll t,w;
  edg(){}
  edg(ll t,ll w=1):t(t),w(w){}
  friend os&O<<(os&o,cs edg&e){rr o<<e.t<<sp<<e.w;}
};

I(J A,J B=A)struct cp{
  A a={};B b={};
  cp(){}
  cp(A a,B b):a(a),b(b){}
  cp(std::pair<A,B>p):a(p.first),b(p.second){}
  cp O-()cs{rr cp(-a,-b);}
  cp&O++(){rr*this+=1;}
  cp&O--(){rr*this+=1;}
  cp&O+=(cs cp&c){a+=c.a,b+=c.b;rr*this;}cp O+(cs cp&c)cs{rr cp(*this)+=c;}
  cp&O-=(cs cp&c){a-=c.a,b-=c.b;rr*this;}cp O-(cs cp&c)cs{rr cp(*this)-=c;}
  I(J T)cp&O+=(cs T&x){a+=x,b+=x;rr*this;}I(J T)cp O+(cs T&x)cs{rr cp(*this)+=x;}
  I(J T)cp&O-=(cs T&x){a-=x,b-=x;rr*this;}I(J T)cp O-(cs T&x)cs{rr cp(*this)-=x;}
  I(J T)cp&O*=(cs T&x){a*=x,b*=x;rr*this;}I(J T)cp O*(cs T&x)cs{rr cp(*this)*=x;}
  bo O==(cs cp&c)cs{rr a==c.a&&b==c.b;}
  bo O<(cs cp&c)cs{rr a!=c.a?a<c.a:b<c.b;}
  bo O>(cs cp&c)cs{rr a!=c.a?a>c.a:b>c.b;}

  friend is&O>>(is&i,cp&c){rr i>>c.a>>c.b;}
  friend os&O<<(os&o,cs cp&c){rr o<<c.a<<sp<<c.b;}
};uu cl=cp<ll>;
I(J A,J B=A,J C=A)struct tr{
  A a={};B b={};C c={};
  tr(){}
  tr(A a,B b,C c):a(a),b(b),c(c){}
  bo O==(cs tr&t)cs{rr a==t.a&&b==t.b&&c==t.c;}

  friend is&O>>(is&i,tr&t){rr i>>t.a>>t.b>>t.c;}
  friend os&O<<(os&o,cs tr&t){rr o<<t.a<<sp<<t.b<<sp<<t.c;}
};uu tl=tr<ll>;

I(J T)decltype(au)rb(T&a){rr*rbegin(a);}
I(J T)au pot(T&a){au r=a.top();a.pop();rr r;}

I(J V)struct ve;
I(J V)constexpr bo isv=0;
I(J V)constexpr bo isv<ve<V>> =1;
I(J V)constexpr bo isv<std::vector<V>> =1;
I(J V)au rawv(V){ifc(isv<V>)rr rawv(V(1)[0]);else rr V();}

I(J V)struct ve:std::vector<V>{
  uu std::vector<V>::vector;
  uu T=decltype(rawv(V()));
  I(J U)ve(cs std::vector<U>&v={}){fe(v,e)this->eb(e);}

  au&O+=(cs ve&u){au&v=*this;fo(i,len(v))v[i]+=u[i];rr v;}
  au&O-=(cs ve&u){au&v=*this;fo(i,len(v))v[i]-=u[i];rr v;}
  au&O^=(cs ve&u){fe(u,e)this->eb(e);rr*this;}
  au&O+=(cs T&x){au&v=*this;fe(v,e)e+=x;rr v;}
  au&O-=(cs T&x){au&v=*this;fe(v,e)e-=x;rr v;}
  au&O*=(cs T&x){au&v=*this;fe(v,e)e*=x;rr v;}
  I(size_t n)au&O+=(cs bitset<n>&a){fo(i,n)(*this)[i]+=a[i];rr*this;}
  I(size_t n)au&O-=(cs bitset<n>&a){fo(i,n)(*this)[i]-=a[i];rr*this;}

  au O+(cs ve&u){rr ve(*this)+=u;}
  au O-(cs ve&u){rr ve(*this)-=u;}
  au O^(cs ve&u){rr ve(*this)^=u;}
  au O+(cs T&x){rr ve(*this)+=x;}au&O++(){rr*this+=1;}
  au O-(cs T&x){rr ve(*this)-=x;}au&O--(){rr*this-=1;}
  au O*(cs T&x){rr ve(*this)*=x;}au O-(){rr ve(*this)*=-1;}

  au lower_bound(cs V&x){rr std::lower_bound(all(*this),x);}
  au upper_bound(cs V&x){rr std::upper_bound(all(*this),x);}
  ve sel(cs std::vector<T>&is){ve r;fe(is,i)r.eb((*this)[i]);rr r;}

  I(J F)au scan(F f){cp<T,bo>r;fe(*this,e)ifc(!isv<V>)r.b?f(r.a,e),r:r={e,1};eif(au s=e.scan(f);s.b)r.b?f(r.a,s.a),r:r=s;rr r;}
  T max(){rr scan([](T&a,cs T&b){a<b?a=b:0;}).a;}

};
I(J T=ll,ll n,ll i=0)au vec(cs ll(&s)[n],T x={}){ifc(n==i+1)rr ve<T>(s[i],x);else{au X=vec<T,n,i+1>(s,x);rr ve<decltype(X)>(s[i],X);}}
I(ll n,J...A)vo setsize(cs ll(&l)[n],A&...a){((a=vec(l,rawv(a))),...);}
I(J T)uu V1=ve<T>;uu u1=V1<ll>;I(J T)uu V2=V1<V1<T>>;uu u2=V2<ll>;
uu strs=V1<str>;uu gra=V2<edg>;uu cls=V1<cl>;uu tls=V1<tl>;

struct io{io(){cin.tie(0)->sync_with_stdio(0);
  cout<<std::fixed<<std::setprecision(15);std::cerr<<nl;}}io;
os&O<<(os&o,cs ulll&x){rr(x<10?o:o<<x/10)<<ll(x%10);}
os&O<<(os&o,cs lll&x){rr o<<str(x<0,'-')<<ulll(zz(x));}
I(size_t n)os&O<<(os&o,cs bitset<n>&b){fo(i,n)o<<b[i];rr o;}
I(J...A)os&O<<(os&o,cs tuple<A...>&t){
  apply([&](cs au&...a){ll i=0;(((o<<a<<str(++i!=sizeof...(a),sp))),...);},t);rr o;}
I(J V)os&O<<(os&o,cs std::vector<V>&v){fe(v,e)o<<e<<str(&e!=&v.back(),isv<V>?nl:sp);rr o;}
I(J...A)vo pp(cs A&...a){ll i=0;((cout<<a<<str(++i!=sizeof...(a),sp)),...);cout<<nl;}
I(J V)is&O>>(is&i,std::vector<V>&v){fe(v,e)i>>e;rr i;}
I(J...A)vo li(A&...a){(cin>>...>>a);}
I(J...A)vo vi(A&...a){fo(i,(len(a)&...))(cin>>...>>a[i]);}
I(J G)au ygi(G&g,ll m=-1,bo f=1){if(m==-1)m=len(g)-1;ift<same<G,u2>,cls,tls>r(m);li(r);
  fe(r,e)ifc(same<G,u2>)g[e.a-=f].eb(e.b-=f);else g[e.a-=f].eb(e.b-=f,e.c);rr r;}

int main(){ll T=1;fo(T)solve();}
vo solve(){
  LL(N,M);
  u2 g(N);
  au es=ygi(g,M);

  u1 dg(N);
  dsu uf(N);

  fe(es,a,b){
    uf.merge(a,b);
    dg[a]--,dg[b]++;
  }

  u2 gs=uf.groups();
  ll ans=0;
  ll C=0;//自己ループなしの孤立点以外の個数．自己ループなしの孤立点には辺がないので連結にする必要なし．
  fe(gs,v){
    if(len(g[v[0]]))C++;

    u1 d=dg.sel(v);

    ll su=0;
    fe(d,x)if(x>0)su+=x;
    ans+=max(su-1,0);
  }
  ans+=C-1;
  pp(ans);
}