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#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>
using namespace std;
long long d[1020];
int fa[1020];
int fnd(int x){
return (x == fa[x])?x:(fa[x] = fnd(fa[x]));
}
void uni(int x,int y){
fa[fnd(x)] = fnd(y);
}
void ini(int n){
for(int i = 0;i < n;i++)
fa[i] = i;
}
int main(){
int n;
long long m;
while(~scanf("%d",&n) && n){
scanf("%I64d",&m);
memset(d,0,sizeof(d));
ini(n + 10);
//读取边,并把对应的端点加入并查集
int a,b;
for(long long i = 0;i < m;i++){
scanf("%d%d",&a,&b);
d[a]++;d[b]++;
uni(a,b);
}
//判断度数
int flg = 1;
for(int i = 1;flg && i <= n;i++)
if(d[i] & 1)
flg = 0;
//判断联通分支数
set <int> s;
if(flg){
for(int i = 1;i <= n;i++){
int f = fnd(i);
if(s.count(f) == 0)
s.insert(f);
}
}
printf("%d\n",flg && (s.size() == 1));
}
return 0;
}
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