/******************************************************************************
Online C++ Compiler.
Code, Compile, Run and Debug C++ program online.
Write your code in this editor and press "Run" button to compile and execute it.
*******************************************************************************/
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
ll N = 1e5 + 10;
string st1,st2;
vector<vector<ll>> v(N,vector<ll>(26)),v1(N,vector<ll>(26));
vector<ll> arr(N);
vector<ll> AC(N),CA(N),AT(N),TA(N),CT(N),TC(N);
void init(string a,string b){
st1=a;
st2=b;
ll n = a.length();
for(ll i=0;i<n;i++){
int x = a[i]-'A';
v[i][x]=1;
}
for(ll i=0;i<n;i++){
int x = b[i]-'A';
v1[i][x]=1;
}
for(ll i=0;i<n;i++){
if(a[i]==b[i]) continue;
if(a[i]=='A'){
if(b[i]=='C') AC[i]++;
else AT[i]++;
}else if(a[i]=='C'){
if(b[i]=='A') CA[i]++;
else CT[i]++;
}else{
if(b[i]=='A') TA[i]++;
else TC[i]++;
}
}
for(ll i=1;i<n;i++) AC[i] = AC[i] + AC[i-1];
for(ll i=1;i<n;i++) AT[i] = AT[i] + AT[i-1];
for(ll i=1;i<n;i++) CA[i] = CA[i] + CA[i-1];
for(ll i=1;i<n;i++) CT[i] = CT[i] + CT[i-1];
for(ll i=1;i<n;i++) TA[i] = TA[i] + TA[i-1];
for(ll i=1;i<n;i++) TC[i] = TC[i] + TC[i-1];
for(ll i=1;i<n;i++){
for(ll j=0;j<26;j++){
v[i][j] = v[i-1][j] + v[i][j];
v1[i][j] = v1[i-1][j] + v1[i][j];
}
}
for(ll i=0;i<n;i++){
arr[i] = (a[i]!=b[i]);
}
for(ll i=1;i<n;i++){
arr[i] += arr[i-1];
}
}
map<int,map<int,int>> mp;
int get_distance(int x,int y){
int c = 0;
for(ll i=0;i<26;i++){
ll am1 = v[y][i];
ll am2 = v1[y][i];
if(x!=0) {
am1 -= v[x-1][i];
am2 -= v1[x-1][i];
}
if(am1!=am2) return -1;
}
int ans = 0;
ll ACc = AC[y],ATc = AT[y],CTc = CT[y],CAc = CA[y],TAc = TA[y],TCc = TC[y];
if(x!=0){
ACc -= AC[x-1];
ATc -= AT[x-1];
CTc -= CT[x-1];
CAc -= CA[x-1];
TAc -= TA[x-1];
TCc -= TC[x-1];
}
ans += min(ACc,CAc);
ans += min(ATc,TAc);
ans += min(CTc,TCc);
ll cn = (ACc + CAc) - 2*min(ACc,CAc) + (ATc + TAc) - 2*min(ATc,TAc) + (CTc + TCc) - 2*min(CTc,TCc);
ans += ((cn / 3)*2);
return ans;
}
// int main()
// {
// init("ATC", "ACT");
// cout<<get_distance(0, 2)<<endl;
// return 0;
// }
