#include "dna.h"
#include <bits/stdc++.h>
using namespace std;
//test case 1
string A;
string B;
void init(string a, string b) {
A = a;
B = b;
}
int get_distance(int x, int y) {
string a = A.substr(x,y);
string b = B.substr(x,y);
long long res = 0;
long long Acounta = 0;
long long Ccounta = 0;
long long Tcounta = 0;
long long Acountb = 0;
long long Ccountb = 0;
long long Tcountb = 0;
for(int i = 0; i < a.size(); i++){
if(a[i] != b[i]){
res++;
}
if(a[i] == 'A') Acounta++;
if(a[i] == 'T') Tcounta++;
if(a[i] == 'C') Ccounta++;
if(b[i] == 'A') Acountb++;
if(b[i] == 'T') Tcountb++;
if(b[i] == 'C') Ccountb++;
}
if(Acounta != Acountb || Ccounta != Ccountb || Tcounta != Tcountb){
return -1;
}
return (res+1)/2;
}
