#include<stdio.h>#include<string.h>#include<algorithm>#define MAXD 210struct Point{ int x, y; bool operator < (const Point &t) const { if(x == t.x) return y < t.y; return x < t.x; }}p[MAXD];struct Vector{ int x, y; bool operator < (const Vector &t) const { return y * t.x < x * t.y; } bool operator != (const Vector &t) const { return y * t.x != x * t.y; }}a[MAXD * MAXD];int N;void init(){ int i; for(i = 0; i < N; i ++) scanf("%d%d", &p[i].x, &p[i].y);}void solve(){ int i, j, n = 0, cnt; std::sort(p, p + N); for(i = 0; i < N; i ++) for(j = i + 1; j < N; j ++) a[n].x = p[j].x - p[i].x, a[n].y = p[j].y - p[i].y, ++ n; std::sort(a, a + n); for(i = cnt = 1; i < n; i ++) if(a[i] != a[i - 1]) ++ cnt; printf("%dn", cnt);}int main(){ while(scanf("%d", &N) == 1) { init(); solve(); } return 0;}
