#include <iostream>
#include <map>
#include <string>
#include <vector>
#include <bits/stdc++.h>
#include <algorithm>
using namespace std;
const int maxn = 1e5 + 10;
int n, m;
vector<int> graph[maxn];
map<pair<int, int>, int> edge_color;
int degColor[maxn][4];
bool visited[maxn];

void dfs(int node, int color) {
    if(visited[node]) {
        return;
    }
    visited[node] = true;

    for(int neighbour: graph[node]) {
        if(edge_color[{node, neighbour}] != 3) continue;
        if(degColor[neighbour][color] != 0) continue;

        edge_color[{node, neighbour}] = color;
        edge_color[{neighbour, node}] = color;

        degColor[node][color]++;

        degColor[neighbour][color]++;

        dfs(neighbour, 3 - color);
        break;

    }

}

bool cmp(int a, int b) {
    return (int) graph[a].size() > (int) graph[b].size();
}
int main() {
    ios_base::sync_with_stdio(false);
    cin >> n >> m;
    memset(degColor, 0, sizeof degColor);
    vector<int> A(m), B(m);
    for(int i = 0; i < m; i++) {
        cin >> A[i] >> B[i];

        int a = A[i] - 1;
        int b = B[i] - 1;
        graph[a].push_back(b);
        graph[b].push_back(a);

        // 3 - uncolored edge
        edge_color[{a, b}] = 3;
        edge_color[{b, a}] = 3;

    }

    vector<int> vertices(n);
    for(int i = 0; i < n; i++) {
        sort(graph[i].begin(), graph[i].end(), cmp);
        vertices[i] = i;
    }

    sort(vertices.begin(), vertices.end(), cmp);

    for(int i = 0; i < n; i++) {
        int node = vertices[i];
        if(degColor[node][1] == 0) {
            memset(visited, false, sizeof visited);
            dfs(node, 1);
        }

        if(degColor[node][2] == 0) {
            memset(visited, false, sizeof visited);
            dfs(node, 2);
        }
    }


    for(int i = 0; i < m; i++) {
        int a = A[i] - 1;
        int b = B[i] - 1;

        if(edge_color[{a, b}] == 3) {
            if(degColor[a][1] == 0 or degColor[b][1] == 0) {
                degColor[a][1]++;
                degColor[b][1]++;
                edge_color[{a, b}] = 1;
                edge_color[{b, a}] = 1;
            }
            else {
                degColor[a][2]++;
                degColor[b][2]++;
                edge_color[{a, b}] = 2;
                edge_color[{b, a}] = 2;
            }
}

    }

    for(int i = 0; i < n; i++) {
        if(degColor[i][1] + degColor[i][2] >= 2 and (degColor[i][1] == 0 or degColor[i][2] == 0)) {
            cout << 0 << endl;
            return 0;
        }
    }

    for(int i = 0; i < m; i++) {
        int a = A[i] - 1, b = B[i] - 1;
        cout << edge_color[{a, b}];
    }


    return 0;
}