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#include<iostream>
#include<cstdio>
#include<vector>
#include<queue>
#define MAX 205
using namespace std;
typedef long long ll;
vector<int>V[MAX];
int color[MAX]; ///white = 0, red = 1 ; blue = 2
int bicoloring(int s) {
queue<int>Q;
Q.push(s);
color[s] = 1;
while (!Q.empty()) {
int u = Q.front();
Q.pop();
int sz = V[u].size();
for (int i = 0; i < sz; i++) {
int v = V[u][i];
if (color[v] == 0) {
if (color[u] == 1) {
color[v] = 2;
} else {
color[v] = 1;
}
Q.push(v);
}
if (color[u] == color[v]) {
return 0;
}
}
}
return 1;
}
int main() {
int n, e;
while (scanf("%d", &n) == 1 && n != 0) {
scanf("%d", &e);
for (int i = 1; i <= e; i++) {
int x, y;
scanf("%d %d", &x, &y);
V[x].push_back(y);
V[y].push_back(x);
}
int check = bicoloring(0);
if (check) {
printf("BICOLORABLE.\n");
} else {
printf("NOT BICOLORABLE.\n");
}
for (int i = 0; i < MAX; i++) {
V[i].clear();
color[i] = 0;
}
}
return 0;
}
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