uva_10004

#include <stdio.h>
#define mx 210

int path[mx][mx];
int color[mx];
int N, L;
int bidir = 1;

void init()
{
    int i, j;

    for (i = 0; i < N; i++)
    {
        color[i] = -1;
        for (j = 0; j < N; j++)
        {
            path[i][j] = 0;
        }
    }
}


int dfs(int x)
{
    int co, i;

    if (1 == color[x])
        co = 2;
    else
        co = 1;


    for (i = 0; i < N; i++)
    {
        if (path[x][i])
        {
            if (-1 == color[i])
            {
                color[i] = co;
                dfs(i);
            }
            else if (i != x && color[i] == color[x])
            {
                bidir = 0;
                return 1;
            }
        }
    }
    return 1;
}

int main()
{

    int i;
    int u, v;

    while (scanf("%d%d", &N, &L))
    {
        init();
        bidir = 1;

        if (0 == N)
            return 0;

        for (i = 0; i < L; i++)
        {
            scanf("%d%d", &u, &v);
            path[u][v] = path[v][u] = 1;
        }

        color[0] = 1;
        dfs(0);


        if (bidir)
            printf("BICOLORABLE.\n");
        else
            printf("NOT BICOLORABLE.\n");

    }

}