#include <iostream>
#include <vector>
#include <stdlib.h>
using namespace std;
vector<string> split(const string &str, char delim){
  vector<string> res;
  size_t current = 0, found;
  while((found = str.find_first_of(delim, current)) != string::npos){
    res.push_back(string(str, current, found - current));
    current = found + 1;
  }
  res.push_back(string(str, current, str.size() - current));
  return res;
}
bool cal(int i,int j,int l,int k,vector<double> &val){
  double kata = (val[i*2]-val[j*2])/(val[i*2+1]-val[j*2+1]);
  double sen1 = kata*(val[2*l] - val[i*2])+val[i*2+1];
  double sen2 = kata*(val[2*k] - val[i*2])+val[i*2+1];
  if((sen1 - val[2*l+1])*(sen2 - val[2*k+1]) > 0 )return true;
  return false;
}
int main(){
  string str;
  while(cin >> str){
    vector<string> s_v = split(str,',');
    vector<double> val(8);
    for(int i = 0;i < 8;i++){
      val[i] = stod(s_v[i]);
    }
    int flag = 0;
    for(int i = 0;i < 4;i++){
      for(int j = 0;j < 4;j++){
	if(i == j)break;
	for(int k = 0;k < 4;k++){
	  if(i == k || j == k)break;
	  for(int l = 0;l < 4;l++){
	    if(i == l || j == l || k == l)break;
	    if(cal(i,j,k,l,val)){
	      flag = 1;
	    }
	  }
	}
      }
    }
    if(flag)cout << "NO" << endl;
    else cout << "YES" << endl;
  }
  return 0;
}