1 #include <iostream>
 2 #include <cstring>
 3 #include <cstdio>
 4 
 5 using namespace std;
 6 
 7 int n,m;
 8 int d[1001];
 9 int pre[1001];
10 
11 int find(int x)
12 {
13     if(pre[x] == 0)
14         return x;
15     int ans = find(pre[x]);
16     pre[x]=ans;
17     return ans;
18 }
19 
20 void unite(int a, int b)
21 {
22     int x = find(a);
23     int y = find(b);
24     if(x != y)
25     {
26         pre[x] = y;
27     }
28 }
29 
30 int main() 
31 {
32     int tmp1, tmp2, count = 0;
33     bool success = true;
34     while(scanf("%d", &n) && n != 0)
35     {
36         memset(d, 0, sizeof(d));
37         memset(pre, 0, sizeof(pre));
38         count = 0;
39         scanf("%d", &m);
40         success = true;
41         for(int i = 1; i <= m; i++)
42         {
43             scanf("%d %d", &tmp1, &tmp2);
44             unite(tmp1, tmp2);
45             d[tmp1]++;
46             d[tmp2]++;
47         }
48         for(int i = 1; i <= n; i++)
49         {
50             if(d[i] % 2 != 0)
51             {
52                 cout << 0 << endl;
53                 success = false;
54                 break;
55             }
56         }
57         if(!success)
58         {
59             continue;
60         }
61         for(int i = 1; i <= n; i++)
62         {
63             if(pre[i] == 0)
64             {
65                 count++;
66             }
67         }
68         if(count > 1)
69         {
70             cout << 0 << endl;
71         }
72         else
73         {
74             cout << 1 << endl;
75         }
76     }
77     return 0;
78 }