#include using namespace std; #include using namespace atcoder; using ll = long long; int n; vector a; void solve(){ for(int _ = 0;_ < 2; _++){ for(int i = 0;i BIT(300000); for(int i = 0;i0){ ll add = min(BIT.sum(i,i+1),BIT.sum(max(-i+300000+1,i+1),300000)); add = max(0ll,add); ans += add; BIT.add(i,-add); BIT.add(300000-1,-add); } } cout< mp; for(int i = 0;i> n; a = vector(n*2); for(auto &i:a)cin >> i; solve(); }