#include<bits/stdc++.h>
using namespace std;char s[100005];int main() {freopen("expression.in", "r", stdin);freopen("expression.out", "w", stdout);scanf("%s", s);int flag = 0, len = strlen(s);for(int i = 0; i < len; i ++) {int t = s[i];if(t >= '0' && t <= '9') {if(flag) {printf("%c", t);flag = 0;if(s[i + 1] != '-' && s[i + 1] != '+' && i + 1 < len) {if(s[i + 1] != '0')    printf("+");else {while(s[i + 1] == '0') {printf("+0"); i ++;}if(s[i + 1] >= '0' && s[i + 1] <= '9')printf("+");}}} else {printf("%c", t);}} else {if(t == '-')    flag = 1;printf("%c", t);}}return 0;
} 

#include<bits/stdc++.h>
#define RG register
using namespace std;int n, m;
struct Node {int u, v, nex;Node(int u = 0, int v = 0, int nex = 0) :u(u), v(v), nex(nex) { }
} Edge[400005];int h[100005], stot = 1;
void add(int u, int v) {Edge[++stot] = Node(u, v, h[u]);h[u] = stot;
}int fae[100005], vis[100005], vise[400005], odd[100005], even[100005], cnto, cnte, dep[100005];
void dfs(int u) {vis[u] = 1;for(int i = h[u]; i; i = Edge[i].nex) {int v = Edge[i].v;if(vise[i])    continue;vise[i] = vise[i ^ 1] = 1;if(vis[v]) {if((dep[v] & 1) == (dep[u] & 1)) {odd[u] ++;odd[v] --;cnto ++;} else {even[u] ++;even[v] --;cnte ++;}} else {fae[v] = i;dep[v] = dep[u] + 1;dfs(v);}}
}void dfs2(int u) {for(int i = h[u]; i; i = Edge[i].nex) {int v = Edge[i].v;if(fae[v] == i) {dfs2(v);odd[u] += odd[v];even[u] += even[v];}}
}int main() {freopen("voltage.in", "r", stdin);freopen("voltage.out", "w", stdout);scanf("%d%d", &n, &m);for(int i = 1; i <= m; i ++) {int u, v;scanf("%d%d", &u, &v);add(u, v);    add(v, u);}dfs(1); dfs2(1);int ans = 0;for(int i = 1; i <= n; i ++)if(fae[i] != 0 && odd[i] == cnto && !even[i])ans ++;if(cnto == 1)    ans ++;printf("%d\n", ans);return 0;
}