#include <string>
#include <vector>
using namespace std;
string solution(string s) {
string answer = "";
string sTemp;
if(s.size()==1)
{
sTemp = s;
}
else if(s.size()%2==0)
{
if(s.size()==2)
{
sTemp = s;
}
sTemp = s.substr((s.size()/2)-1,2);
printf("여기맞나요");
}
else
{
int iTemp = ((s.size()-1)/2);
sTemp = s.at(iTemp);
}
answer = sTemp;
return answer;
}