#include<bits/stdc++.h>
using namespace std;

typedef long long ll;

const int maxn=1e6+5;
int a[maxn], b[maxn], siz[maxn], siz2[maxn], id[maxn];
int tfa[20005], fa[20005], col[maxn], num[20005];
vector<int> v1[20005], v2[20005];

bitset<5005> f;

int find(int x) {
    if(fa[x]!=x) return fa[x]=find(fa[x]);
    return x;
}

void merge(int u,int v) {
    u=find(u), v=find(v);
    fa[u]=v;
    return ;
}

bitset<5005> F[20005];

void gz(int i,int j) {
    if(!i) return ;
    // cout<<id[i]<<'\n';
    if(j>=siz[id[i]]-siz2[id[i]]&&F[i-1][j-siz[id[i]]+siz2[id[i]]]) {
        gz(i-1,j-siz[id[i]]+siz2[id[i]]);
        for(auto x:v1[id[i]]) col[x]=1;
        for(auto x:v2[id[i]]) col[x]=2;
    }else {
        gz(i-1,j);
        for(auto x:v2[id[i]]) col[x]=1;
        for(auto x:v1[id[i]]) col[x]=2;
    }
    return ;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);
    int n,m; cin>>n>>m;
    n<<=1;
    for(int i=1;i<=m;i++) cin>>a[i]>>b[i];
    for(int i=1;i<=2*n;i++) fa[i]=i;
    for(int i=m;i>=1;i--) {
        int u=find(a[i]), v=find(b[i]);
        int uu=find(a[i]+n), vv=find(b[i]+n);
        if(u==v) continue;
        if(u==vv) continue;
        // cout<<"! "<<a[i]<<' '<<b[i]<<'\n';
        for(int j=1;j<=2*n;j++) tfa[j]=fa[j], siz[j]=siz2[j]=0;
        fa[u]=vv, fa[uu]=v;
        for(int j=1;j<=n;j++) siz[find(j)]++;
        for(int j=n+1;j<=2*n;j++) siz2[find(j)]++;
        int sum=0;
        f.reset(); f[0]=1;
        for(int j=1;j<=2*n;j++) {
            if(find(j)!=j) continue;
            if(j<=n&&find(j+n)<j||j>n&&find(j-n)<j) continue;
            if(siz[j]<siz2[j]) swap(siz[j],siz2[j]);
            sum+= siz2[j];
            num[siz[j]-siz2[j]]++;
            // f|=(f<<siz[j]-siz2[j]);
        }
        for(int j=1;j<=n;j++) {
            for(int k=0;(1<<k)<=num[j];k++) {
                f|=(f<<(j<<k));
                num[j]-= (1<<j);
            }
            if(num[j]) f|=(f<<(j*num[j])), num[j]=0;
        }
        if(!f[n/2-sum]) {
            for(int j=1;j<=2*n;j++) fa[j]=tfa[j];
        }
    }
    for(int i=1;i<=2*n;i++) siz[i]=siz2[i]=0;
    for(int i=1;i<=n;i++) siz[find(i)]++, v1[find(i)].push_back(i);
    for(int i=n+1;i<=2*n;i++) siz2[find(i)]++, v2[find(i)].push_back(i-n);
    int sum=0, num=0;
    F[0][0]=1;
    for(int i=1;i<=2*n;i++) {
        if(find(i)!=i||i<=n&&find(i+n)<i||i>n&&find(i-n)<i) continue;
        if(siz[i]<siz2[i]) swap(siz[i],siz2[i]), swap(v1[i],v2[i]);
        sum+= siz2[i];
        id[++num]=i;
        F[num]=F[num-1]|(F[num-1]<<siz[i]-siz2[i]);
    }
    if(!F[num][n/2-sum]) {
        cout<<"AA???\n";
    }else {
        gz(num,n/2-sum);
        for(int i=1;i<=n;i++) cout<<col[i]-1; cout<<'\n';
    }
    return 0;
}