1 #include<algorithm>
 2 #include<iostream>
 3 #include<cstdlib>
 4 #include<cstring>
 5 #include<cstdio>
 6 #include<vector>
 7 #include<map>
 8 using std::map;
 9 using std::cin;
10 using std::cout;
11 using std::endl;
12 using std::find;
13 using std::sort;
14 using std::pair;
15 using std::vector;
16 using std::multimap;
17 #define pb(e) push_back(e)
18 #define sz(c) (int)(c).size()
19 #define mp(a, b) make_pair(a, b)
20 #define all(c) (c).begin(), (c).end()
21 #define iter(c) decltype((c).begin())
22 #define cls(arr,val) memset(arr,val,sizeof(arr))
23 #define cpresent(c, e) (find(all(c), (e)) != (c).end())
24 #define rep(i, n) for (int i = 0; i < (int)(n); i++)
25 #define tr(c, i) for (iter(c) i = (c).begin(); i != (c).end(); ++i)
26 const int N = 1010;
27 typedef unsigned long long ull;
28 struct Node  { int to, next; };
29 struct Euler {
30     Node G[N];
31     bool vis[N];
32     int tot, inq[N], head[N];
33     inline void init() {
34         tot = 0;
35         cls(vis, false), cls(inq, 0), cls(head, -1);
36     }
37     inline void add_edge(int u, int v) {
38         G[tot].to = v; G[tot].next = head[u]; head[u] = tot++;
39     }
40     inline void dfs(int u) {
41         vis[u] = true;
42         for (int i = head[u]; ~i; i = G[i].next) {
43             if (!vis[G[i].to]) dfs(G[i].to);
44         }
45     }
46     inline void work(int n, int m) {
47         init();
48         int u, v;
49         bool f = true;
50         rep(i, m) {
51             scanf("%d %d", &u, &v);
52             inq[u]++, inq[v]++;
53             add_edge(u, v), add_edge(v, u);
54         }
55         rep(i, n) {
56             if (inq[i + 1] & 1) { f = false; break; }
57         }
58         if (!f) { puts("0"); return; }
59         dfs(1);
60         rep(i, n) {
61             if (!vis[i + 1]) { f = false; break; }
62         }
63         puts(f ? "1" : "0");
64     }
65 }go;
66 int main() {
67 #ifdef LOCAL
68     freopen("in.txt", "r", stdin);
69     freopen("out.txt", "w+", stdout);
70 #endif
71     int n, m;
72     while (~scanf("%d", &n), n) {
73         scanf("%d", &m);
74         go.work(n, m);
75     }
76     return 0;
77 }