#include<iostream>

 #include<cstdio>

 #include<cmath>

 #include<algorithm>

 #include<queue>

 #include<cstring>

 #define PAU putchar(' ')

 #define ENT putchar('\n')

 using namespace std;

 const int maxn=+,maxm=+;

 int low[maxn],dfn[maxn],s[maxn],beg[maxn],top,scc,cz;bool ins[maxn];

 struct ted{int x,y;ted*nxt;}adj[maxm],*fch[maxn],*ms=adj;

 void add(int x,int y){*ms=(ted){x,y,fch[x]};fch[x]=ms++;return;}

 void tarjan(int u){

     low[u]=dfn[u]=++cz;ins[u]=true;s[++top]=u;

     for(ted*e=fch[u];e;e=e->nxt){

         int v=e->y;if(!dfn[v])tarjan(v),low[u]=min(low[u],low[v]);

         else if(ins[v])low[u]=min(low[u],dfn[v]);

     }if(low[u]==dfn[u]){

         scc++;int t=-;while(t!=u)beg[t=s[top--]]=scc,ins[t]=false;

     }return;

 }

 inline int read(){

     int x=,sig=;char ch=getchar();

     while(!isdigit(ch)){if(ch=='-')sig=-;ch=getchar();}

     while(isdigit(ch))x=*x+ch-'',ch=getchar();

     return x*=sig;

 }

 inline void write(int x){

     if(x==){putchar('');return;}if(x<)putchar('-'),x=-x;

     int len=,buf[];while(x)buf[len++]=x%,x/=;

     for(int i=len-;i>=;i--)putchar(buf[i]+'');return;

 }

 int n,m;

 void init(){

     n=read();m=read();int x,y;

     while(m--){x=read();y=read();add(x,y);}

     for(int i=;i<=n;i++) if(!dfn[i]) tarjan(i);

     for(int i=;i<=n;i++){

         printf("%d:%d\n",i,beg[i]);

     }

     return;

 }

 void work(){

     return;

 }

 void print(){

     return;

 }

 int main(){init();work();print();return ;}

 /*

 5 5

 1 2

 2 3

 3 4

 4 5

 5 1

 */