10004.cpp

#include <bits/stdc++.h>
using namespace std;
vector<int> v[201];
int N, flag;
void bfs(int n) {
    int i;
    queue<int> q;
    q.push(n);
    int view[220] = {0};
    view[n] = 1;
    while (q.size()) {
        int n = q.front();
        for (i = 0; i < v[n].size(); i++) {
            if (view[v[n][i]] == 0) {
                q.push(v[n][i]);
                view[v[n][i]] = view[n] + 1;
            } else if (view[v[n][i]] % 2 == view[n] % 2) {
                flag = 1;
                return;
            }
        }
        q.pop();
    }
}

int main() {
    int i, j, k, l, n, e;
    while (scanf("%d", &N)) {
        if (N == 0) return 0;
        scanf("%d", &e);
        for (i = 0; i < e; i++) {
            scanf("%d %d", &k, &l);
            v[k].push_back(l);
            v[l].push_back(k);
        }
        flag = 0;
        bfs(0);
        if (flag == 1)
            puts("NOT BICOLORABLE.");
        else
            puts("BICOLORABLE.");
        for (i = 0; i < 201; i++) {
            v[i].clear();
        }
    }
    return 0;
}