对拓扑序建线段树，每条边等价于一个区间覆盖，没了
#include<iostream>
#include<cstring>
#include<cstdio>
#include<algorithm>
#include<climits>
#include<queue>
#define N 500010
#define M 1000010
#define INF (INT_MAX/2-10)
#define gc getchar()
#define debug(x) cerr<<#x<<"="<<x
#define sp <<" "
#define ln <<endl
using namespace std;
struct edges{
int to,pre;
}e[M];int h[N],d[N],etop,u[M],v[M],f[N],g[N],t[N],id[N];queue<int> q;
inline int add_edge(int u,int v)
{ return e[++etop].to=v,d[v]++,e[etop].pre=h[u],h[u]=etop; }
inline int getdis(int n,int m,int *f,int *u,int *v)
{
etop=0,memset(h,0,sizeof(int)*(n+1));
while(!q.empty()) q.pop();int c=0;
memset(d,0,sizeof(int)*(n+1)),memset(f,0,sizeof(int)*(n+1));
for(int i=1;i<=m;i++) add_edge(u[i],v[i]);
for(int i=1;i<=n;i++) if(!d[i]) q.push(i),f[i]=0,t[id[i]=++c]=i;
while(!q.empty())
{
int x=q.front();q.pop();
for(int i=h[x],y;i;i=e[i].pre)
{
y=e[i].to,f[y]=max(f[y],f[x]+1);
if(!(--d[y])) q.push(y),t[id[y]=++c]=y;
}
}
return c;
}
struct segment{
int l,r,v;segment *ch[2];
}*rt;
int build(segment* &rt,int l,int r)
{
rt=new segment,rt->l=l,rt->r=r,rt->v=0;if(l==r) return 0;
int mid=(l+r)>>1;return build(rt->ch[0],l,mid),build(rt->ch[1],mid+1,r);
}
int update(segment* &rt,int s,int t,int v)
{
if(s>t) return 0;
int l=rt->l,r=rt->r,mid=(l+r)>>1;
if(s<=l&&r<=t) return rt->v=max(rt->v,v);
if(s<=mid) update(rt->ch[0],s,t,v);
if(mid<t) update(rt->ch[1],s,t,v);return 0;
}
int query(segment* &rt,int p)
{
int l=rt->l,r=rt->r,mid=(l+r)>>1;if(l==r) return rt->v;
return max(rt->v,query(rt->ch[p>mid],p));
}
inline int inn()
{
int x,ch;while((ch=gc)<'0'||ch>'9');
x=ch^'0';while((ch=gc)>='0'&&ch<='9')
x=(x<<1)+(x<<3)+(ch^'0');return x;
}
int main()
{
// freopen("a.in","r",stdin),freopen("std.out","w",stdout);
int n=inn(),m=inn(),ans=INF,x=0;
for(int i=1;i<=m;i++) u[i]=inn(),v[i]=inn();
getdis(n,m,g,v,u),getdis(n,m,f,u,v),build(rt,1,n);
// for(int i=1;i<=n;i++) debug(i)sp,debug(f[i])sp,debug(g[i])sp,debug(t[i])ln;
for(int i=1,x,y,w;i<=m;i++) update(rt,x=id[u[i]]+1,y=id[v[i]]-1,w=f[u[i]]+g[v[i]]+1);//,debug(x)sp,debug(y)sp,debug(w)ln;
for(int i=2,v=f[t[1]];i<=n;i++) update(rt,i,n,v),v=max(v,f[t[i]]);
for(int i=n-1,v=g[t[n]];i;i--) update(rt,1,i,v),v=max(v,g[t[i]]);
for(int i=1,v;i<=n;i++) if((v=query(rt,id[i]))<ans) ans=v,x=i;
return !printf("%d %d\n",x,ans);
}