#include <bits/stdc++.h>
#include "dna.h"
using namespace std;
typedef long long ll;
const int MXN = 1e5 +10;
int ac[MXN] = {0};
int ca[MXN] = {0};
int at[MXN] = {0};
int ta[MXN] = {0};
int ct[MXN] = {0};
int tc[MXN] = {0};
int N;
void init(std::string a, std::string b) {
N = a.length();
for(int i=0; i<N; i++){
if(i!=0){
ac[i] = ac[i-1];
ca[i] = ca[i-1];
at[i] = at[i-1];
ta[i] = ta[i-1];
ct[i] = ct[i-1];
tc[i] = tc[i-1];
}
if(a[i]=='A' && b[i]=='C') ac[i]++;
if(a[i]=='C' && b[i]=='A') ca[i]++;
if(a[i]=='A' && b[i]=='T') at[i]++;
if(a[i]=='T' && b[i]=='A') ta[i]++;
if(a[i]=='C' && b[i]=='T') ct[i]++;
if(a[i]=='T' && b[i]=='C') tc[i]++;
}
// for(int i=0; i<N; i++) cout<<ca[i]<<" ";
// cout<<"\n";
}
int get_distance(int x, int y) {
ll tac, tca, tat, tta, tct, ttc;
tac = ac[y]; tca = ca[y]; tat = at[y];
tta = ta[y]; tct = ct[y]; ttc = tc[y];
if(x!=0){
tac -= ac[x-1]; tca -= ca[x-1]; tat -= at[x-1];
tta -= ta[x-1]; tct -= ct[x-1]; ttc -= tc[x-1];
}
ll ans = 0LL;
ans += (min(tac,tca) + min(tat,tta) + min(tct,ttc));
ll t1, t2, t3;
if(tac<tca){
tca -= tac;
tac = 0;
t1 = tca;
}
else{
tac -= tca;
tca = 0;
t1 = tac;
}
if(tat<tta){
tta -= tat;
tat = 0;
t2 = tta;
}
else{
tat -= tta;
tta = 0;
t2 = tat;
}
if(tct<ttc){
ttc -= tct;
tct = 0;
t3 = ttc;
}
else{
tct -= ttc;
ttc = 0;
t3 = tct;
}
// cout<<"t1="<<t1<<" t2="<<t2<<" t3="<<t3<<"\n";
if(!((t1==t2) && (t2==t3))) return -1;
if((t1==tac && t2==tct && t3==tta) || (t1==tca && t2==ttc && t3==tat)){
ans += (t1*2);
return ans;
}
return -1;
}
