#include <bits/stdc++.h>
#define SIZE 300005
#define MOD 1000000007LL
#define INF 1 << 30
#define LLINF 1LL << 60
#define REP(i,n) for(int i=0;i<n;i++)
#define FOR(i,a,b) for(int i=a;i<=b;i++)
#define DOWN(i,b,a) for(int i=b;i>=a;i--)
#define SET(a,c) memset(a,c,sizeof a)
#define FORALL(i,c) for(__typeof((c).begin())i=(c).begin();i!=(c).end();++i)
#define FOREACH(i,c) for(auto (i) : (c))
#define BIT(i,j) ((i)>>(j))&1
#define ALL(o) (o).begin(), (o).end()
#define ERASE(o) (o).erase(unique((o).begin(),(o).end()), (o).end())
#define SQ(x) ((x)*(x))
using namespace std;
typedef long long ll;
typedef pair<ll,ll> Pll;
typedef pair<int, int> Pii;
typedef pair<double, double> Pdd;
typedef complex<double> dcomplex;
template<typename T> inline void priv(vector<T>a){REP(i,a.size()){cerr<<a[i]<<((i==a.size()-1)?"\n":" ");}}
ll gcd(ll a,ll b){int c=max(a,b);int d=min(a,b);return c==0||d==0?c:gcd(c%d,d);}
ll lcm(ll a,ll b){return a==0||b==0?0:a*b/gcd(a,b);}
ll fact(ll a){ll b=1;FOR(i,1,a)b*=i;return b;}

class P
{
public:
  double x,y;
  P(){};P(double x,double y):x(x),y(y){};
  P operator+(const P&q){P t;t.x=x+q.x;t.y=y+q.y;return t;}
  P operator+=(const P&q){x+=q.x;y+=q.y;return *this;}
  P operator-(const P&q){P t;t.x=x-q.x;t.y=y-q.y;return t;}
  P operator-=(const P&q){x-=q.x;y-=q.y;return *this;}
  template<typename T> P operator*(T d){return P(x*d,y*d);}
  template<typename T> P operator*=(T d){x*=d;y*=d;return *this;}
  template<typename T> P operator/(T d){return P(x/d,y/d);}
  template<typename T> P operator/=(T d){x/=d;y/=d;return *this;}
  bool operator<(const P&q){return (x!=q.x)?(x<q.x):(y<q.y);}
  bool operator>(const P&q){return (x!=q.x)?(x>q.x):(y>q.y);}
  double norm(void){return sqrt(x*x+y*y);}
  double arg(void){return acos(x/this->norm())*P(1,0).sign(*this);}
  P rotate(double t){double c=cos(t),s=sin(t);return P(c*x-s*y,s*x+c*y);}
  P reverseX(void){return P(-x,y);}
  P reverseY(void){return P(x,-y);}
  P unit(void){return (*this)/(*this).norm();}
  P floor(void){return P((int)x,(int)y);}
  double dot(const P&q){return x*q.x+y*q.y;}
  double det(const P&q){return x*q.y-y*q.x;}
  int sign(const P&q){double d = (*this).det(q); return (d>0)-(d<0);}
  bool on_seg(P p1,P p2,P q){return (p1-q).det(p2-q)==0&&(p1-q).dot(p2-q)<=0;}
  P intersection(P p1,P p2,P q1,P q2){return p1+(p2-p1)*((q2-q1).det(q1-p1)/(q2-q1).det(p2-p1));}
};

int main()
{
  int n, m = 0; cin >> n;
  vector<P> a(n);
  REP(i,n) scanf("%lf,%lf",&a[i].x,&a[i].y);
  REP(i,n) REP(j,n) if(i!=j)
  {
    int c1 = 0, c2 = 0;
    double d = (a[j]-a[i]).norm()/2;
    P e = (a[j]-a[i]).rotate(M_PI/2).unit();
    P p = (a[i]+a[j])/2+e*sqrt(1-d*d);
    P q = (a[i]+a[j])/2-e*sqrt(1-d*d);
    REP(k,n) if((p-a[k]).norm() <= 1) c1++;
    REP(k,n) if((q-a[k]).norm() <= 1) c2++;
    m = max(m,max(c1,c2));
  }
  cout << m << endl;
}