#include "dna.h"
#include <iostream>
#include <bits/stdc++.h>
#define ll long long
using namespace std;
const ll maxn = 2*1e5+5, INF = 4e18+9;
int pf[maxn][3][3];
void init(std::string a, std::string b) {
int n = a.size();
a = ' ' + a;
b = ' ' + b;
map<char, int> mp;
mp['A'] = 0;
mp['T'] = 1;
mp['C'] = 2;
for(int i = 1; i <= n; i++){
for(int p = 0; p < 3; p++){
for(int q = 0; q < 3; q++){
pf[i][p][q] = pf[i-1][p][q];
}
}
int p = mp[a[i]], q = mp[b[i]];
pf[i][p][q]++;
}
}
int get_distance(int x, int y) {
x++; y++;
vector<vector<int>> d(3, vector<int>(3, 0));
vector<int> cnt(3, 0);
for(int p = 0; p < 3; p++){
for(int q = 0; q < 3; q++){
d[p][q] = pf[y][p][q] - pf[x-1][p][q];
cnt[p] += d[p][q];
cnt[q] -= d[p][q];
}
}
for(int i = 0; i < 3; i++){
if(cnt[i] != 0) return -1;
}
int ans = 0, lt = 0;
for(int p = 0; p < 3; p++){
for(int q = 0; q < p; q++){
int diff = min(d[p][q], d[q][p]);
d[p][q] -= diff;
d[q][p] -= diff;
ans += diff;
lt = max(d[p][q], d[q][p]);
}
}
ans += lt*2;
return ans;
}
