#include "dna.h"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define all(x) x.begin(), x.end()
#define rep(i, l, n) for (int i = l; i < (n); ++i)
#define sz(x) (int)x.size()
const char nl = '\n';
const int mod = 1e9+7;
const int NMAX = 1e5+10;
const int inf = 1e9+10;
int p0[2][NMAX], p1[2][NMAX], p2[2][NMAX];
int N, res[NMAX];
string s, t;
void init(string a, string b) {
N = sz(a); s = a, t = b;
rep(i, 0, 2)
rep(j, 0, N) {
if (i == 0) {
if (a[j] == 'A')p0[0][j] += 1;
if (a[j] == 'C')p1[0][j] += 1;
if (a[j] == 'T')p2[0][j] += 1;
} else {
if (b[j] == 'A')p0[1][j] += 1;
if (b[j] == 'C')p1[1][j] += 1;
if (b[j] == 'T')p2[1][j] += 1;
}
if (j) {
p0[i][j] += p0[i][j-1];
p1[i][j] += p1[i][j-1];
p2[i][j] += p2[i][j-1];
}
}
vector<int> nol, bir, iki;
rep(i, 0, N) {
if (a[i] == 'A')nol.push_back(i);
if (a[i] == 'C')bir.push_back(i);
if (a[i] == 'T')iki.push_back(i);
}
for (int i = N-1; i >= 0; --i) {
if (b[i] == 'A') {
if (nol.empty())continue;
res[i] = 1; nol.pop_back();
}
if (b[i] == 'C') {
if (bir.empty())continue;
res[i] = 1; bir.pop_back();
}
if (b[i] == 'A') {
if (iki.empty())continue;
res[i] = 1; iki.pop_back();
}
if (i<N-1)res[i] += res[i+1];
}
}
int get_distance(int x, int y) {
bool ok = true;
//rep(i, 0, 3) {
int a = p0[0][y]-(x?p0[0][x-1]:0);
int b = p0[1][y]-(x?p0[1][x-1]:0);
ok &= (b==a);
//}
a = p1[0][y]-(x?p1[0][x-1]:0);
b = p1[1][y]-(x?p1[1][x-1]:0);
ok &= (b==a);
a = p2[0][y]-(x?p2[0][x-1]:0);
b = p2[1][y]-(x?p2[1][x-1]:0);
ok &= (b==a);
if (!ok)return -1;
vector<int> nol, bir, iki;
int ans = 0;
rep(i, x, y+1) {
if (s[i] == 'A')nol.push_back(i);
if (s[i] == 'C')bir.push_back(i);
if (s[i] == 'T')iki.push_back(i);
}
for (int i = y; i >= x; --i) {
if (!nol.empty() && nol.back() > i)nol.pop_back();
if (!bir.empty() && bir.back() > i)bir.pop_back();
if (!iki.empty() && iki.back() > i)iki.pop_back();
if (t[i] == 'A') {
if (nol.empty())continue;
ans += 1; nol.pop_back();
}
if (t[i] == 'C') {
if (bir.empty())continue;
ans += 1; bir.pop_back();
}
if (t[i] == 'T') {
if (iki.empty())continue;
ans += 1; iki.pop_back();
}
}
return ans;
//return res[x]-(y+1<N?res[y+1]:0);
}
