#include<bits/stdc++.h>
using namespace std;
struct node {
int x, y;
node(int xx = 0, int yy = 0) {
x = xx;
y = yy;
}
}NODE[600];
int t = 1;
struct para {
int a, b, c;
para(int aa, int bb, int cc) {
a = aa;
b = bb;
c = cc;
}
bool operator < (const para &p) const {
if (a != p.a) return a < p.a;
else {
if (b != p.b) return b < p.b;
else return c < p.c;
}
}
};
set <para> s;
int gcd(int a, int b) {return b == 0 ? a : gcd(b, a % b);}
int main()
{
for (int i = 1; i <= 20; i++) {
for (int j = 1; j <= 21; j++) {
NODE[t++] = node(i, j);
}
}
for (int i = 1; i <= 419; i++) {
for (int j = i + 1; j <= 420; j++) {
int a = NODE[i].y - NODE[j].y;
int b = NODE[j].x - NODE[i].x;
int c = ((-NODE[i].y) * (NODE[j].x - NODE[i].x)) + (NODE[i].x * (NODE[j].y - NODE[i].y));
int num = gcd(a, gcd(b, c));
a /= num; b /= num; c /= num;
s.insert(para(a, b, c));
}
}
cout << s.size() << endl;
return 0;
}