#include "dna.h"
#include <bits/stdc++.h>
using namespace std;
#define a A
#define b B
#define x X
#define y Y
#define pb push_back
int n;
vector<int> a;
vector<int> b;
vector<vector<int> > pref_cnt_a;
vector<vector<int> > pref_cnt_b;
vector<vector<vector<int> > > pref;
void solve() {
pref_cnt_a.assign(1 + n, vector<int> (3, 0));
pref_cnt_b.assign(1 + n, vector<int> (3, 0));
for(int i = 1; i <= n; i++) {
pref_cnt_a[i] = pref_cnt_a[i - 1];
pref_cnt_a[i][a[i]]++;
pref_cnt_b[i] = pref_cnt_b[i - 1];
pref_cnt_b[i][b[i]]++;
}
pref.assign(1 + n, vector<vector<int> > (3, vector<int> (3, 0)));
for(int i = 1; i <= n; i++) {
pref[i] = pref[i - 1];
pref[i][a[i]][b[i]]++;
}
}
int query(int l, int r) {
int res = 0;
vector<int> cnt_a(3, 0);
vector<int> cnt_b(3, 0);
for(int i = 0; i < 3; i++) {
cnt_a[i] = pref_cnt_a[r][i] - pref_cnt_a[l - 1][i];
cnt_b[i] = pref_cnt_b[r][i] - pref_cnt_b[l - 1][i];
if(cnt_a[i] != cnt_b[i]) {
return -1;
}
}
vector<vector<int> > v(3, vector<int> (3, 0));
for(int i = 0; i < 3; i++) {
for(int j = 0; j < 3; j++) {
v[i][j] = pref[r][i][j] - pref[l - 1][i][j];
}
}
int mini = -1;
mini = min(v[0][1], v[1][0]);
res += mini;
v[0][1] -= mini;
v[1][0] -= mini;
mini = min(v[2][1], v[1][2]);
res += mini;
v[2][1] -= mini;
v[1][2] -= mini;
mini = min(v[0][2], v[2][0]);
res += mini;
v[0][2] -= mini;
v[2][0] -= mini;
mini = -1;
int maxi = 0;
for(int i = 0; i < 3; i++) {
for(int j = 0; j < 3; j++) {
maxi = max(maxi, v[i][j]);
}
}
res += 2 * maxi;
return res;
}
#undef a
#undef b
#undef x
#undef y
void init(string a, string b) {
n = a.size();
A.assign(n + 1, 0);
B.assign(n + 1, 0);
for(int i = 1; i <= n; i++) {
if(a[i - 1] == 'A') {
A[i] = 0;
}
if(a[i - 1] == 'T') {
A[i] = 1;
}
if(a[i - 1] == 'C') {
A[i] = 2;
}
if(b[i - 1] == 'A') {
B[i] = 0;
}
if(b[i - 1] == 'T') {
B[i] = 1;
}
if(b[i - 1] == 'C') {
B[i] = 2;
}
}
solve();
}
int get_distance(int x, int y) {
return query(x + 1, y + 1);
}
