#include "dna.h"
#include<bits/stdc++.h>
#pragma GCC optimize("-O3")
#define ll int
#define ld long double
#define vl vector<ll>
#define vi vector<int>
#define pii pair<int, int>
#define pll pair<ll, ll>
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define f first
#define s second
#define pb push_back
#define p_b pop_back
using namespace std;
const ll sz = 1e5+5;
ll cnt[3][sz], cnt2[3][sz], pref[sz], i, n;
void init(string a, string b) {
a = '#' + a;
b = '#' + b;
n = a.size();
for(i = 1; i <= n; i++)
pref[i] = pref[i-1] + (a[i] != b[i]);
for(i = 1; i <= n; i++)
{
cnt[0][i] = cnt[0][i-1];
cnt[1][i] = cnt[1][i-1];
cnt[2][i] = cnt[2][i-1];
cnt2[0][i] = cnt2[0][i-1];
cnt2[1][i] = cnt2[1][i-1];
cnt2[2][i] = cnt2[2][i-1];
if(a[i] == 'A')
cnt[0][i] = cnt[0][i-1] + 1;
if(a[i] == 'C')
cnt[1][i] = cnt[1][i-1] + 1;
if(a[i] == 'T')
cnt[2][i] = cnt[2][i-1] + 1;
if(b[i] == 'A')
cnt2[0][i] = cnt2[0][i-1] + 1;
if(b[i] == 'C')
cnt2[1][i] = cnt2[1][i-1] + 1;
if(b[i] == 'T')
cnt2[2][i] = cnt2[2][i-1] + 1;
}
}
int get_distance(int x, int y) {
x++, y++;
ll acnt1 = cnt[0][y] - cnt[0][x-1];
ll ccnt1 = cnt[1][y] - cnt[1][x-1];
ll tcnt1 = cnt[2][y] - cnt[2][x-1];
ll acnt2 = cnt2[0][y] - cnt2[0][x-1];
ll ccnt2 = cnt2[1][y] - cnt2[1][x-1];
ll tcnt2 = cnt2[2][y] - cnt2[2][x-1];
//cout << acnt1 << ' ' << ccnt1 << ' ' << tcnt1 << ' ' << acnt2 << ' ' << ccnt2 << ' ' << tcnt2 << "\n";
if(acnt1 != acnt2 || ccnt1 != ccnt2 || tcnt1 != tcnt2)
return -1;
return max(0, pref[y] - pref[x-1] - 1);
}
/*
int main()
{
string a, b;
cin >> a >> b;
init(a, b);
ll q;
cin >> q;
while(q--)
{
int x, y;
cin >> x >> y;
cout << get_distance(x, y) << "\n";
}
}
*/
