#pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") #include <bits/stdc++.h> using namespace std; #define pb push_back #define all(a) a.begin(),a.end() typedef long long ll; typedef pair<int,int> pii; typedef pair<ll,ll> pll; typedef unsigned long long ull; typedef vector<int> vi; const int mxn = 600+1; vector<pii> g[mxn]; ll dp[mxn][400]; void dfs(int u = 1, int col = 0){ for(auto [v,c] : g[u]){ dfs(v,c); for(int i = 0; i < 400; i++) dp[u][i] += dp[v][i]; } if(g[u].empty()){ for(int i = 0; i <= 399; i++) dp[u][i] = abs(i-col); }else{ for(int i = 399; i >= 0; i--) for(int j = i; j >= 0; j--) dp[u][i] = min(dp[u][i],dp[u][j] + abs((i-j)-col)); } } void solve(){ int n,m; cin >> n >> m; for(int i = 2; i <= n+m; i++){ int p,c; cin >> p >> c; g[p].emplace_back(pii{i,c}); } dfs(); cout << *min_element(dp[1],dp[1]+400); } signed main(){ cin.tie(0)->sync_with_stdio(0); int t = 1; // cin >> t; while(t--){solve();} }