#include using namespace std; using ll = long long; int main() { cin.tie(nullptr); ios::sync_with_stdio(false); int N,M; cin>>N>>M; vector> G(N); for(int i=0;i>u>>v; u--;v--; G[u].push_back(v); G[v].push_back(u); } vector D(N,1e9); queue Q; Q.push(0); D[0]=0; while(!Q.empty()){ int p=Q.front(); Q.pop(); for(int v:G[p]){ if(D[v]<=D[p]+1)continue; D[v]=D[p]+1; Q.push(v); } } vector AN(N+1,0); for(int i=0;i=2)AN[i]+=AN[i-2]; cout<