#include <bits/stdc++.h>
#include "dna.h"
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
#define MASK(i) (1ULL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
template <class T1, class T2>
bool maximize(T1 &a, T2 b){
if (a < b) {a = b; return true;}
return false;
}
template <class T1, class T2>
bool minimize(T1 &a, T2 b){
if (a > b) {a = b; return true;}
return false;
}
template <class T>
void printArr(T& container, string separator = " ", string finish = "\n", ostream &out = cout){
for(auto item: container) out << item << separator;
out << finish;
}
template <class T>
void remove_dup(vector<T> &a){
sort(ALL(a));
a.resize(unique(ALL(a)) - a.begin());
}
int convert(char c){
if (c == 'A') return 0;
if (c == 'T') return 1;
if (c == 'C') return 2;
return 3;
}
const int N = 1e5 + 69;
int n;
int cnt[N][3];
int cnt_pair[N][3][3];
void init(string a, string b){
n = a.size();
for(int i = 1; i<=n; ++i){
for(int j = 0; j<3; ++j) cnt[i][j] = cnt[i-1][j];
cnt[i][convert(a[i-1])]++;
cnt[i][convert(b[i-1])]--;
for(int x = 0; x < 3; ++x) for(int y = 0; y < 3; ++y) cnt_pair[i][x][y] = cnt_pair[i-1][x][y];
cnt_pair[i][convert(a[i-1])][convert(b[i-1])]++;
}
}
int get_distance(int l, int r){
l++; r++;
for(int x = 0; x< 3; ++x) if (cnt[r][x] - cnt[l-1][x] != 0) return -1;
int graph[3][3]; memset(graph, 0, sizeof graph);
for(int x = 0; x < 3; ++x) for(int y = 0; y < 3; ++y) graph[x][y] = cnt_pair[r][x][y] - cnt_pair[l-1][x][y];
int ans = 0;
for(int x = 0; x < 3; ++x) for(int y = x + 1; y < 3; ++y) {
int cur = min(graph[x][y], graph[y][x]);
ans += cur;
graph[x][y] -= cur; graph[y][x] -= cur;
}
for(int x = 0; x < 3; ++x) for(int y = 0; y < 3; ++y) if (y != x){
int z = 3 - x - y;
int cur = min({graph[0][x], graph[1][y], graph[2][z]});
ans += cur * 2;
graph[0][x] -= cur; graph[1][y] -= cur; graph[2][z] -= cur;
}
return ans;
}
// int main(void){
// ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
// init("ATACAT", "ACTATA");
// cout << get_distance(1, 3) << "\n";
// cout << get_distance(4, 5) << "\n";
// cout << get_distance(3, 5) << "\n";
// return 0;
// }
