#pragma GCC optimize("O3")
#include "dna.h"
#include <bits/stdc++.h>
using namespace std;
const int MAX = 1e5 + 5;
int n;
int pre[MAX][3][3];
map<char, int> mp = {{'A', 0}, {'C', 1}, {'T', 2}};
void init(string a, string b) {
n = a.size();
for (int i = 0; i < n; i++)
{
pre[i + 1][mp[a[i]]][mp[b[i]]]++;
}
for (int i = 1; i <= n; i++)
{
for (int j = 0; j < 3; j++)
{
for (int k = 0; k < 3; k++)
{
pre[i][j][k] += pre[i - 1][j][k];
}
}
}
}
int get_distance(int x, int y) {
y += 1;
int arr[3][3];
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 3; j++)
{
arr[i][j] = pre[y][i][j] - pre[x][i][j];
}
}
for (int i = 0; i < 3; i++)
{
int s1 = 0, s2 = 0;
s1 += arr[i][0] + arr[i][1] + arr[i][2];
s2 += arr[0][i] + arr[1][i] + arr[2][i];
if(s1 != s2){
return -1;
}
}
int s = 0, ans = 0;
for (int i = 0; i < 3; i++)
{
for (int j = i + 1; j < 3; j++)
{
if(arr[i][j] < arr[j][i]) swap(arr[i][j], arr[j][i]);
ans += arr[j][i];
s += arr[i][j] - arr[j][i];
}
}
ans += s / 3 * 2;
return ans;
}
