#include<cstdio>

 #include<cstdlib>

 #include<cstring>

 #include<algorithm>

 #include<iostream>

 using namespace std;

 // const int maxN=100;

 // int a[maxN+10];

 const int N=,M=;

 int dfn[N],low[N],first[N],bfir[N],v[N],c[N],s[N],id[];

 int n,m,al,bl,sl,num,mx,cnt;

 struct node{

     int x,y,next,tmp;

 }a[*M],b[*M];

 int minn(int x,int y){return x<y ? x:y;}

 void ins(int x,int y)

 {

     al++;a[al].tmp=;

     a[al].x=x;a[al].y=y;a[al].next=first[x];first[x]=al;

 }

 void anins(int x,int y)

 {

     bl++;b[bl].tmp=;

     b[bl].x=x;b[bl].y=y;b[bl].next=bfir[x];bfir[x]=bl;

 }

 void tarjan(int x,int fa)

 {

     dfn[x]=low[x]=++num;

     s[++sl]=x;

     for(int i=first[x];i;i=a[i].next)

     {

         if(a[i].tmp) continue;

         a[i%== ? i-:i+].tmp=;

         int y=a[i].y;

         if(!dfn[y])

         {

             tarjan(y,x);

             low[x]=minn(low[x],low[y]);

         }

         else if(!c[y]) low[x]=minn(low[x],dfn[y]);

     }

     if(dfn[x]==low[x])

     {

         cnt++;

         int z=;

         while()

         {

             z=s[sl];sl--;

             v[z]=;

             c[z]=cnt;

             if(z==x) break;

         }

     }

 }

 void dfs(int x,int fa,int dep,int tmp)

 {

     if(dep>mx) mx=dep,id[tmp]=x;

     for(int i=bfir[x];i;i=b[i].next)

     {

         int y=b[i].y;

         if(y==fa) continue;

         dfs(y,x,dep+,tmp);

     }

 }

 int main()

 {

     freopen("input.txt","r",stdin);

     freopen("output.txt","w",stdout);

     scanf("%d%d",&n,&m);

     al=;sl=;bl=;num=;cnt=;

     memset(bfir,,sizeof(bfir));

     memset(first,,sizeof(first));

     memset(dfn,,sizeof(dfn));

     memset(low,,sizeof(low));

     memset(c,,sizeof(c));

     for(int i=;i<=m;i++)

     {

         int x,y;

         scanf("%d%d",&x,&y);

         ins(x,y);ins(y,x);

     }

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

     {

         if(!dfn[i]) num=,tarjan(i,);

     }

     // for(int i=1;i<=n;i++) printf("c [ %d ] = %d\n",i,c[i]);

     for(int i=;i<=*m;i++)

     {

         int x=a[i].x,y=a[i].y;

         if(c[y]==c[x]) continue;

         anins(c[x],c[y]);

         // printf("%d -- > %d\n",c[x],c[y]);

     }

     mx=,dfs(,,,);

     mx=,dfs(id[],,,);

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

         if(c[i]==id[]) {printf("%d ",i);break;}

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

         if(c[i]==id[]) {printf("%d\n",i);break;}

     // printf("%d %d\n",id[0],id[1]);

     return ;

 }