#include "dna.h"
#include <bits/stdc++.h>
using namespace std;
const int kN = 1e5 + 10;
int n, pre[kN][3][3];
map<char, int> mp;
void init(std::string a, std::string b) {
mp['A'] = 0, mp['T'] = 1, mp['C'] = 2;
n = a.length();
for(int i = 0; i < n; i++) {
if(i) {
for(int x = 0; x < 3; x++) {
for(int y = 0; y < 3; y++) pre[i][x][y] = pre[i - 1][x][y];
}
}
pre[i][mp[a[i]]][mp[b[i]]]++;
}
}
int get_distance(int l, int r) {
auto Getnum = [&](int x, int y) {
if(!l) return pre[r][x][y];
else return pre[r][x][y] - pre[l - 1][x][y];
};
int num[3][3] = {};
for(int i = 0; i < 3; i++) {
for(int j = 0; j < 3; j++) num[i][j] = Getnum(i, j);
}
int cnt = 0;
for(int i = 0; i < 3; i++) {
int j = (i + 1) % 3;
int mn = min(num[i][j], num[j][i]);
cnt += mn;
num[i][j] -= mn, num[j][i] -= mn;
}
bool flag = 1;
for(int i = 0; i < 3; i++) flag &= (num[i][(i + 1) % 3] == num[0][1]);
for(int i = 0; i < 3; i++) flag &= (num[(i + 1) % 3][i] == num[1][0]);
if(!flag) return -1;
else {
cnt += 2 * (num[0][1] + num[1][0]);
return cnt;
}
}
