#include "dna.h"
#include <bits/stdc++.h>
#define endl '\n'
#define pb push_back
#define F first
#define S second
#define all(v) v.begin(), v.end()
#define allr(v) v.rbegin(), v.rend()
using namespace std;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
string a, b;
void init(string A, string B){
a = A;
b = B;
}
int get_distance(int x, int y){
string s = s.substr(x, y + 1), t = s.substr(x, y + 1);
int cnt = 0;
for(int i = x; x <= y; i++)
if(s[i] != t[i]) cnt++;
if(cnt % 2) return -1;
return cnt / 2;
}
