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#include <iostream>
#include <cstdio>
#include <cstring>
#include <cctype>
#include <algorithm>
#include <vector>
#include <string>
#include <stack>
#include <queue>
#include <map>
#include <cmath>
#define For(a,x,y) for (int a = x; a <= y; ++a)
#define Forw(a,x,y) for (int a = x; a < y; ++a)
#define Bak(a,y,x) for (int a = y; a >= x; --a)
#define RED 1;
#define BLUE -1;
namespace FastIO {
inline int getint() {
int s = 0, x = 1;
char ch = getchar();
while (!isdigit(ch)) {
if (ch == '-') x = -1;
ch = getchar();
}
while (isdigit(ch)) {
s = s * 10 + ch - '0';
ch = getchar();
}
return s * x;
}
inline void __basic_putint(int x) {
if (x < 0) {
x = -x;
putchar('-');
}
if (x >= 10) __basic_putint(x / 10);
putchar(x % 10 + '0');
}
inline void putint(int x, char external) {
__basic_putint(x);
putchar(external);
}
}
namespace Solution {
const int MAXN = 200 + 10;
const int MAXM = MAXN * MAXN + 10;
struct Node {
int now, weight;
Node() { now = weight = 0; }
bool operator < (const Node &that) const {
return weight > that.weight;
}
};
struct Edge {
int now, next;
Edge() { now = next = 0; }
} edge[MAXM];
int head[MAXN], cnt, n, l;
short color[MAXN];
inline void Init() {
cnt = 0;
memset(head, 0, sizeof(head));
memset(color, 0, sizeof(color));
for (int i = 1; i <= cnt + 5; ++i) {
Edge tmp;
tmp.now = tmp.next = 0;
edge[i] = tmp;
}
}
inline void addEdge(int prev, int next) {
edge[++cnt].now = next;
edge[cnt].next = head[prev];
head[prev] = cnt;
}
inline bool BoynextdoorFirstSearch(int start = 1) {
std::queue<int> q;
q.push(start);
color[start] = RED;
while (!q.empty()) {
int now = q.front();
q.pop();
for (int e = head[now]; e; e = edge[e].next) {
int to = edge[e].now;
if (color[to] == color[now]) return false;
if (color[to] == 0) q.push(to);
if (color[now] == 1) {
color[to] = -1;
} else {
color[to] = 1;
}
}
}
return true;
}
}
signed main() {
#define HANDWER_FILE
#ifndef HANDWER_FILE
freopen("testdata.in", "r", stdin);
freopen("testdata.out", "w", stdout);
#endif
using namespace Solution;
using FastIO::getint;
while (true) {
n = getint();
if (n == 0) break;
l = getint();
Init();
for (int i = 1; i <= l; ++i) {
int prev = getint();
int next = getint();
addEdge(prev, next);
addEdge(next, prev);
}
if (BoynextdoorFirstSearch()) puts("BICOLORABLE.");
else puts("NOT BICOLORABLE.");
}
return 0;
}
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