#include "dna.h"
#include<bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define pb push_back
#define vll vector<ll>
#define pll pair<ll, ll>
typedef long long ll;
namespace{
const ll mxN=1e5+5;
ll n;
ll pre[mxN][6];
ll val[mxN][6];
ll pre2[mxN][3];
ll val2[mxN][3];
}
void init(string a, string b) {
n=a.length();
memset(pre, 0, sizeof(pre));
memset(val, 0, sizeof(val));
for(ll i=0;i<n;i++){
if(a[i]==b[i]) continue;
if(a[i]=='T' && b[i]=='A'){
val[i][0]++;
}
else if(a[i]=='A' && b[i]=='T'){
val[i][1]++;
}
else if(a[i]=='T' && b[i]=='C'){
val[i][2]++;
}
else if(a[i]=='C' && b[i]=='T'){
val[i][3]++;
}
else if(a[i]=='C' && b[i]=='A'){
val[i][4]++;
}
else if(a[i]=='A' && b[i]=='C'){
val[i][5]++;
}
}
for(ll i=0;i<n;i++){
for(ll j=0;j<6;j++){
pre[i+1][j]=pre[i][j]+val[i][j];
}
}
}
int get_distance(int x, int y) {
ll tep[6]={};
for(ll i=0;i<6;i++){
tep[i]=pre[y+1][i]-pre[x][i];
}
if((tep[1]+tep[5])!=(tep[0]+tep[4])){
return -1;
}
if((tep[0]+tep[2])!=(tep[1]+tep[3])){
return -1;
}
if((tep[3]+tep[4])!=(tep[2]+tep[5])){
return -1;
}
ll ans=0;
for(ll i=0;i<6;i+=2){
ans+=min(tep[i], tep[i+1]);
}
ans+=2*(max(tep[0], tep[1])-min(tep[0], tep[1]));
return (int) ans;
}
