#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using ull = unsigned long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pld = pair<ld, ld>;
#define fi first
#define se second
#define left BAO
#define right ANH
#define pb push_back
#define pf push_front
#define mp make_pair
#define ins insert
#define btpc __builtin_popcount
#define btclz __builtin_clz
#define sz(x) (int)(x.size());
#define all(x) x.begin(), x.end()
#define debug(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int d4x[4] = {1, 0, -1, 0}; int d4y[4] = {0, 1, 0, -1};
int d8x[8] = {0, 1, 1, 1, 0, -1, -1, -1};
int d8y[8] = {1, 1, 0, -1, -1, -1, 0, 1};
template<class X, class Y>
bool minimize(X &x, const Y &y) {
if (x > y)
{
x = y;
return true;
}
return false;
}
template<class X, class Y>
bool maximize(X &x, const Y &y) {
if (x < y)
{
x = y;
return true;
}
return false;
}
const int MOD = 1e9 + 7; //998244353
template<class X, class Y>
void add(X &x, const Y &y) {
x = (x + y);
if(x >= MOD) x -= MOD;
}
template<class X, class Y>
void sub(X &x, const Y &y) {
x = (x - y);
if(x < 0) x += MOD;
}
/* Author : Le Ngoc Bao Anh, 12A5, LQD High School for Gifted Student*/
const ll INF = 1e9;
const int N = 1e5 + 10;
int d[N][5][5], f[5][5];
int a[N], b[N], pref[N][5];
void init(string A, string B) {
int n = A.size();
A = "#" + A;
B = "#" + B;
for(int i = 1; i <= n; i++) {
if(A[i] == 'A') a[i] = 0;
if(A[i] == 'T') a[i] = 1;
if(A[i] == 'C') a[i] = 2;
if(B[i] == 'A') b[i] = 0;
if(B[i] == 'T') b[i] = 1;
if(B[i] == 'C') b[i] = 2;
for(int j = 0; j < 3; j++) {
pref[i][j] = pref[i - 1][j] + (a[i] == j) - (b[i] == j);
}
for(int j = 0; j < 3; j++) {
for(int k = 0; k < 3; k++) {
d[i][j][k] = d[i - 1][j][k];
}
}
d[i][a[i]][b[i]]++;
}
}
int get_distance(int l, int r) {
l++; r++;
for(int i = 0; i < 3; i++) {
if(pref[r][i] != pref[l - 1][i]) return -1;
}
int ans = 0;
for(int i = 0; i < 3; i++) {
for(int j = 0; j < 3; j++) {
f[i][j] = d[r][i][j] - d[l - 1][i][j];
}
}
for(int i = 0; i < 3; i++) {
for(int j = i + 1; j < 3; j++) {
int x = min(f[i][j], f[j][i]);
ans += x;
f[i][j] -= x;
f[j][i] -= x;
}
}
int p = 0;
for(int i = 0; i < 3; i++) {
for(int j = i + 1; j < 3; j++) {
if(f[i][j]) p = f[i][j];
}
}
ans += 2 * p;
return ans;
}
