#include <bits/stdc++.h>
using namespace std;
int n;
vector<int> a , b , c , a_t , b_t , c_t , pref;
void init(string s , string t){
n = (int)s.length();
a.resize(n + 1); b.resize(n + 1); c.resize(n + 1); a_t.resize(n + 1); b_t.resize(n + 1); c_t.resize(n + 1); pref.resize(n + 1);
for(int i = 0 ; i < n ; i++){
pref[i+1] = pref[i] + (s[i] != t[i]);
}
for(int i = 0 ; i < n ; i++){
a[i + 1] = a[i] + (s[i] == 'A');
a_t[i + 1] = a_t[i] + (t[i] == 'A');
b[i + 1] = b[i] + (s[i] == 'T');
b_t[i + 1] = b_t[i] + (t[i] == 'T');
c[i + 1] = c[i] + (s[i] == 'C');
c_t[i + 1] = c_t[i] + (t[i] == 'C');
}
return ;
}
int get_distance(int x , int y){
if(a[y + 1] - a[x] == a_t[y + 1] - a_t[x] && b[y + 1] - b[x] == b_t[y + 1] - b_t[x] && c[y + 1] - c[x] == c_t[y + 1] - c_t[x]){
int p = pref[y + 1] - pref[x];
return (p + 1) / 2;
}
else return -1;
}
