#include "dna.h"
#include<bits/stdc++.h>
using namespace std;
const int N = 1e5+5;
int cnt[2][N][3];
int dif[N][3][3];
int dak[500];
void init(string a, string b) {
int n = a.size();
a = "?" + a;
b = "?" + b;
dak['A'] = 0;
dak['T'] = 1;
dak['C'] = 2;
for (int i=1; i<=n; i++) {
for (int j=0; j<3; j++) {
cnt[0][i][j] = cnt[0][i-1][j];
cnt[1][i][j] = cnt[1][i-1][j];
}
cnt[0][i][dak[a[i]]]++;
cnt[1][i][dak[b[i]]]++;
for (int j=0; j<3; j++) {
for (int k=0; k<3; k++) {
dif[i][j][k] = dif[i-1][j][k] + (dak[a[i]] == i && dak[b[i]] == k);
}
}
}
}
int get (int id, int l, int r, int u) {
return cnt[id][r][u] - cnt[id][l-1][u];
}
int get_dif (int l, int r, int u, int v) {
return dif[r][u][v] - dif[l-1][u][v];
}
int get_distance(int l, int r) {
l++; r++;
for (int i=0; i<3; i++) if (get(0,l,r,i) != get (1,l,r,i)) return -1;
int cnt = r -l + 1;
int res = 0;
for (int i=0; i<3; i++) {
cnt -= get_dif (l,r,i,i);
for (int j=0; j<i; j++) {
int val = min (get_dif(l,r,i,j), get_dif(l,r,j,i));
res += val;
cnt -= val;
}
}
assert(cnt%3==0);
res += cnt/3*2;
return res;
}
/*int main() {
string a,b; cin >> a >> b;
init(a,b);
int q; cin >> q;
while (q--) {
int l,r; cin >> l >> r;
cout << get_distance(l,r) << '\n';
}
}*/
