#include "dna.h"
#include <bits/stdc++.h>
using namespace std;
int pre[100005][3][3];
int n;
string a, b;
void init(std::string A, std::string B) {
a = A, b = B;
n = a.length();
for (int i = 0; i < n; ++i) {
if (a[i] == 'A') a[i] = 'a';
else if (a[i] == 'C') a[i] = 'b';
else a[i] = 'c';
if (b[i] == 'A') b[i] = 'a';
else if (b[i] == 'C') b[i] = 'b';
else b[i] = 'c';
}
for (int i = 0; i < n; ++i) {
pre[i][a[i] - 'a'][b[i] - 'a']++;
}
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];
}
}
// for (int i = 0; i < 3; ++i) {
// for (int j = 0; j < 3; ++j) cout << pre[n - 1][i][j] << ' ';
// cout << endl;
// }
}
int arr[3][3];
int get_distance(int x, int y) {
// cout << y << endl;
memset(arr, 0, sizeof arr);
for (int i = 0; i < 3; ++i) {
for (int j = 0; j < 3; ++j) {
arr[i][j] = pre[y][i][j];
if (x) arr[i][j] -= pre[x - 1][i][j];
// cout << pre[n - 1][i][j] << ' ';
// cout << arr[i][j] << ' ';
}
// cout << endl;
// cout << endl;
}
int ans = 0;
for (int rep = 0; rep < 100; ++rep) {
for (int i = 0; i < 3; ++i) {
for (int j = 0; j < 3; ++j) {
if (i == j) continue;
if (arr[i][j] == 0) continue;
int take = arr[i][j];
take = min(take, arr[j][i]);
arr[i][j] -= take;
arr[j][i] -= take;
ans += take;
}
}
}
for (int rep = 0; rep < 100; ++rep) {
for (int i = 0; i < 3; ++i) {
for (int j = 0; j < 3; ++j) {
if (i == j) continue;
if (arr[i][j] == 0) continue;
int take = arr[i][j];
take = min(take, arr[j][i]);
arr[i][j] -= take;
arr[j][i] -= take;
ans += take;
if (arr[i][j] == 0) continue;
for (int k = 0; k < 3; ++k) {
if (arr[j][k] == 0) continue;
if (j == k) continue;
int take = arr[i][j];
take = min(take, arr[j][k]);
arr[i][j] -= take;
arr[j][k] -= take;
arr[i][k] += take;
ans += take;
}
}
}
}
int can = 1;
for (int i = 0; i < 3; ++i) for (int j = 0; j < 3; ++j) if (i != j && arr[i][j] != 0) can = 0;
if (!can) {
// int cnt = 0;
vector<vector<int>> cnt(2, vector<int> (3, 0));
for (int i = x; i <= y; ++i) {
++cnt[0][a[i] - 'a'];
++cnt[1][b[i] - 'a'];
}
int cann = 1;
for (int i = 0; i < 3; ++i) if (cnt[0][i] != cnt[1][i]) cann = 0;
assert(cann == 0);
// cout << cnt[0][0] << ' ' << cnt[1][0] << endl;
}
if (!can) return -1;
return ans;
}
