#include #define ALL(v) std::begin(v),std::end(v) using lint=long long; using ld=long double; templateusing numr=std::numeric_limits; int main(){ std::cin.tie(nullptr);std::ios_base::sync_with_stdio(false); std::cout.setf(std::ios_base::fixed);std::cout.precision(15); lint n;std::cin>>n; std::vector>>a(n); for(lint i=0;i>x;x--; a.at(x).emplace_back(i,j); } lint ans=0; for(auto&&v:a){ std::vectorb(2*n); for(auto[i,j]:v){ for(lint k:{n+i-j+1,n+i+j+1})if(k<2*n)b.at(k)++; } b.at(0)=-n; std::partial_sum(ALL(b),b.begin()); b.at(0)=0; for(auto[i,j]:v){ b.at(0)+=n+i; } std::partial_sum(ALL(b),b.begin()); ans+=*std::min_element(b.begin()+n,b.begin()+2*n); } std::cout<