#include<bits/stdc++.h>
using namespace std;
int main(){
int n,m,x,y;
cin>>n>>m;
vector<int>a[n+1];
for(int i=1;i<=m;++i){
cin>>x>>y;
a[x].push_back(y);
}
for(int i=1;i<=n;++i){
for(int j=0;j<a[i].size();++j) cout<<a[i][j]<<' ';
cout<<endl;
}
return 0;
}