Help me in solving QTOO_2523 problem.. which cases i have missed in given code?

help
,
1

My issue

ghyg

My code

#include <iostream>
#include<algorithm>
using namespace std;

int main() {
	// your code goes here
	int t;
	cin>>t;
	while(t--){
	    int n;
	    cin>>n;
	    string s;
	    cin>>s;
	    unordered_map<char,int>mp;
	    for(int i=0;i<n;i++){
	     // mp[i]=s[i];
	      mp[s[i]]++;
	    }
	    int c2=0,count=0;
	    for(auto ele:mp){
	       // if(ele.second%2!=0){
	       //     count++;
	       // }
	         if(ele.second%2==0) c2++;
	    }
	    if(c2>=1 && s.length()>=2){
	        cout<<s.length()-2<<endl;
	    }
	    else cout<<"-1"<<endl;
	}
	return 0;
}

Problem Link: QTOO_2523 Problem - CodeChef

2

@deepakjdh31
The condition u get the answer will be if u find any two characters same so just check
if(ele.second>=2)