#include <bits/stdc++.h>
#include "dna.h"
using namespace std;
string A, B;
void init(string a, string b){
A = a, B = b;
}
int get_distance(int x, int y){
int a = 0, t = 0, bad = 0;
for(int i = x; i <= y; ++i){
a += (A[i] == 'A');
a -= (B[i] == 'A');
t += (A[i] == 'T');
t -= (B[i] == 'T');
bad += A[i] != B[i];
}
if(a == 0 && t == 0) return bad / 2;
return -1;
}
/*int main(){
#ifndef ONLINE_JUDGE
freopen("inp.in", "r", stdin);
freopen("output.out", "w", stdout);
#endif
ios_base::sync_with_stdio(0);
cin.tie(nullptr); cout.tie(nullptr);
return 0;
}*/
