题目传送门
/*
水题,就是用三点共线的式子来判断射击次数
*/
#include <cstdio>
#include <cmath>
#include <string>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <map>
#include <set>
#include <vector>
using namespace std;
const int MAXN = 1e3 + ;
int x[MAXN], y[MAXN];
bool used[MAXN];
int main(void)
{
//freopen ("B.in", "r", stdin);
int n, x0, y0;
while (~scanf ("%d%d%d", &n, &x0, &y0))
{
memset (used, , sizeof (used));
for (int i=; i<=n; ++i)
{
scanf ("%d%d", &x[i], &y[i]);
x[i] -= x0; y[i] -= y0;
}
int cnt = ;
for (int i=; i<=n; ++i)
{
if (!used[i])
{
cnt++;
for (int j=i; j<=n; ++j)
{
if (!used[j] && (x[i] * y[j] == x[j] * y[i]))
used[j] = ;
}
}
}
printf ("%d\n", cnt);
}
return ;
}