C ++：无效的参数“ stoi（）文件已中止”即将到来

Question

所以下面是我的代码，文件中的内容以及抛出“ std :: invalid_argument”实例后不断显示为终止的错误消息   what（）：stoi 中止

任何帮助将不胜感激！谢谢enter code here

---------------------------- CODE ------------------

#include <iostream>
#include <fstream>
#include <string>
using namespace std;
const int size=6;
int main()
{
   int friendsNumber[size]={0};
   int maxFriends=0;
   string friendName;
   ifstream myfile;
   myfile.open("myfile.txt");
   while(getline(myfile,friendName,','))
   {
      friendsNumber[stoi(friendName)]++;
      getline(myfile,friendName);
      friendsNumber[stoi(friendName)]++;
   }
   for(int count=1;count<=5;count++)
   {
      if(friendsNumber[stoi(friendName)]>maxFriends)
         maxFriends=friendsNumber[stoi(friendName)];
   }
   cout<<maxFriends;
return 0;
}

---what's inside myfile.txt---------
1,2
2,3
4,5
3,4
1,5
1,4



-----------Error-----------
terminate called after throwing an instance of 'std::invalid_argument'
  what():  stoi
Aborted