#include<bits/stdc++.h> #define int long long using namespace std; int n,m,fa[600005],w[600005],rd[600005]; int rt[600005],lc[600005],rc[600005],v[600005],dis[600005],tot,ans; int getnew(int x){ v[++tot]=x;return tot; } int merge(int x,int y){ if(!x||!y)return x+y; if(v[y]>v[x])swap(x,y); rc[x]=merge(rc[x],y); if(dis[lc[x]]<dis[rc[x]])swap(lc[x],rc[x]); dis[x]=dis[rc[x]]+1; return x; } signed main(){ scanf("%lld%lld",&n,&m);dis[0]=-1; for(int i=2;i<=n+m;i++){ scanf("%lld%lld",&fa[i],&w[i]);rd[fa[i]]++; ans+=w[i]; } for(int i=n+m;i>=2;i--){ int l=0,r=0; if(i<=n)while(rd[i]-->1)rt[i]=merge(lc[rt[i]],rc[rt[i]]); r=v[rt[i]],rt[i]=merge(lc[rt[i]],rc[rt[i]]); l=v[rt[i]],rt[i]=merge(lc[rt[i]],rc[rt[i]]); rt[i]=merge(rt[i],merge(getnew(l+w[i]),getnew(r+w[i]))); rt[fa[i]]=merge(rt[fa[i]],rt[i]); } while(rd[1]--)rt[1]=merge(lc[rt[1]],rc[rt[1]]); while(rt[1])ans=ans-v[rt[1]],rt[1]=merge(lc[rt[1]],rc[rt[1]]); printf("%lld",ans); }

fireworks.cpp: In function 'int main()':
fireworks.cpp:18:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   18 |  scanf("%lld%lld",&n,&m);dis[0]=-1;
      |  ~~~~~^~~~~~~~~~~~~~~~~~
fireworks.cpp:20:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   20 |   scanf("%lld%lld",&fa[i],&w[i]);rd[fa[i]]++;
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~