#include<bits/stdc++.h>
using namespace std;
#define optimizar_io ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);cout.setf(ios::fixed);cout.precision(0);
#pragma GCC optimize("Ofast")
typedef long long ll;
ll AT[100002]={ },AC[100002]={ },TC[100002]={ };
ll TA[100002]={ },CA[100002]={ },CT[100002]={ };
ll n;
void init(string a, string b)
{
n=a.size();
for(int i=0; i<n; i++)
{
if(a[i]=='A'&&b[i]=='T')AT[i+1]=1;
if(a[i]=='A'&&b[i]=='C')AC[i+1]=1;
if(a[i]=='T'&&b[i]=='C')TC[i+1]=1;
if(a[i]=='T'&&b[i]=='A')TA[i+1]=1;
if(a[i]=='C'&&b[i]=='A')CA[i+1]=1;
if(a[i]=='C'&&b[i]=='T')CT[i+1]=1;
if(i>0)
{
AT[i+1]+=AT[i];
AC[i+1]+=AC[i];
TC[i+1]+=TC[i];
TA[i+1]+=TA[i];
CA[i+1]+=CA[i];
CT[i+1]+=CT[i];
}
}
}
int get_distance(int x,int y)
{
x++;
y++;
ll AT1=AT[y]-AT[x-1], TA1=TA[y]-TA[x-1], CT1=CT[y]-CT[x-1];
ll AC1=AC[y]-AC[x-1], TC1=TC[y]-TC[x-1], CA1=CA[y]-CA[x-1];
ll a1=AT1+AC1, t1=TC1+TA1 ,c1=CA1+CT1;
ll a2=TA1+CA1, t2=AT1+CT1 ,c2=AC1+TC1;
//cout<<a1<<a2<<" "<<t1<<t2<<" "<<c1<<c2;
if(a1!=a2||t1!=t2||c1!=c2)return -1;
else
{
return min(AT1,TA1)+min(AC1,CA1)+min(CT1,TC1)+(max(AT1,TA1)-min(AT1,TA1))*2;
}
}
