#include using namespace std; typedef signed long long ll; #undef _P #define _P(...) (void)printf(__VA_ARGS__) #define FOR(x,to) for(x=0;x<(to);x++) #define FORR(x,arr) for(auto& x:arr) #define ITR(x,c) for(__typeof(c.begin()) x=c.begin();x!=c.end();x++) #define ALL(a) (a.begin()),(a.end()) #define ZERO(a) memset(a,0,sizeof(a)) #define MINUS(a) memset(a,0xff,sizeof(a)) //------------------------------------------------------- int N; ll X[4040],Y[4040]; void solve() { int i,j,k,l,r,x,y; string s; double pi=4*atan(1); cin>>N; vector V; FOR(i,N) { cin>>X[i]>>Y[i]; ll g=__gcd(abs(X[i]),abs(Y[i])); if(g==0) { i--; N--; continue; } X[i]/=g; Y[i]/=g; V.push_back(atan2(Y[i],X[i])); } sort(ALL(V)); FOR(i,N) { V.push_back(V[i]+2*pi); } ll ret=0; FOR(i,N) { j=i; while(V[j]-V[i]<=pi) j++; y=j; for(x=i+1;x