#include <algorithm>
#include <utility>
#include <cstdio>
#include <set>
#define MOD 998244353
#define mp std::make_pair
typedef long long ll;
int x[405], y[405], seq[405];
std::set<std::pair<int, int> > se;
inline bool comp(int a, int b)
{
if (x[a] == x[b])
return y[a] < y[b];
return x[a] < x[b];
}
inline bool same(int a, int b, int c)
{
return (x[b] - x[a]) * (y[c] - y[a]) == (x[c] - x[a]) * (y[b] - y[a]);
}
inline int quick_pow(int a, int n)
{
int res = 1;
while (n)
{
if (n & 1)
res = (ll)res * a % MOD;
a = (ll)a * a % MOD;
n >>= 1;
}
return res;
}
int main()
{
// freopen("ARC082-E.in", "r", stdin);
int n;
scanf("%d", &n);
for (int i = 0; i < n; i++)
scanf("%d%d", x + i, y + i);
int ans = (quick_pow(2, n) - n - 1 + MOD) % MOD;
for (int i = 0; i < n; i++)
{
for (int j = 0; j < n; j++)
{
if (i == j)
continue;
int cnt = 0;
for (int k = 0; k < n; k++)
{
if (same(i, j, k))
seq[cnt++] = k;
}
std::sort(seq, seq + cnt, comp);
se.insert(mp(seq[0], seq[1]));
}
}
for (auto line : se)
{
int cnt = 0;
for (int i = 0; i < n; i++)
{
if (same(line.first, line.second, i))
cnt++;
}
ans = (ans - quick_pow(2, cnt) + cnt + 1 + MOD) % MOD;
}
printf("%d\n", ans);
return 0;
}
./Main.cpp: In function ‘int main()’:
./Main.cpp:36:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
scanf("%d", &n);
^
./Main.cpp:38:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d", x + i, y + i);
^