#include <iostream>
#include <bits/stdc++.h>
#include "dna.h";
typedef long long ll;
using namespace std;
const int mxN=1e5+5;
int d[100005];
int numbersA[mxN][3], numbersB[mxN][3];
int n,q,x,y;
string f,s;
int aa=0, ta=0, ca=0,ab=0, tb=0, cb=0, difference=0;
int rat=0, rta=0, rac=0,rca=0, rtc=0, rct=0;
vector<pair<int,int>>replaceA (mxN,{0,0});
vector<pair<int,int>>replaceT (mxN,{0,0});
vector<pair<int,int>>replaceC (mxN,{0,0});
void init(string a, string b)
{
for(int i=0; i<a.size(); i++)
{
if(a[i]!=b[i])
{
difference++;
}
d[i]=difference;
if(a[i]=='A')
{
aa++;
if(b[i]=='T') rat++;
if(b[i]=='C') rac++;
}
else if (a[i]=='T')
{
ta++;
if(b[i]=='A') rta++;
if(b[i]=='C') rtc++;
}
else if (a[i]=='C')
{
ca++;
if(b[i]=='A') rca++;
if(b[i]=='T') rct++;
}
numbersA[i][0]=aa;
numbersA[i][1]=ta;
numbersA[i][2]=ca;
replaceA[i].first=rat;
replaceA[i].second=rac;
replaceT[i].first=rta;
replaceT[i].second=rtc;
replaceC[i].first=rca;
replaceC[i].second=rct;
if(b[i]=='A')
{
ab++;
}
else if (b[i]=='T')
{
tb++;
}
else if (b[i]=='C')
{
cb++;
}
numbersB[i][0]=ab;
numbersB[i][1]=tb;
numbersB[i][2]=cb;
}
}
int get_distance(int x,int y)
{
int ans=0;
int div=d[y];
int da1=numbersA[y][0], dt1=numbersA[y][1], dc1=numbersA[y][2], da2=numbersB[y][0], dt2=numbersB[y][1], dc2=numbersB[y][2] ;
int rati=replaceA[y].first, rtai=replaceT[y].first, raci=replaceA[y].second, rcai=replaceC[y].first, rtci=replaceT[y].second, rcti=replaceC[y].second;
if(x!=0)
{
div-=d[x-1];
da1-=numbersA[x-1][0];
dt1-=numbersA[x-1][1];
dc1-=numbersA[x-1][2];
da2-=numbersB[x-1][0];
dt2-=numbersB[x-1][1];
dc2-=numbersB[x-1][2];
rati-=replaceA[x].first;
rtai-=replaceT[x].first;
raci-=replaceA[x].second;
rcai-=replaceC[x].first;
rtci-=replaceT[x].second;
rcti-=replaceC[x].second;
}
if(da1==da2 && dt1==dt2 && dc1==dc2)
{
ans+=min(rati,rtai);
div-=(min(rati,rtai))*2;
ans+=min(raci,rcai);
div-=(min(raci,rcai))*2;
ans+=min(rtci,rcti);
div-=(min(rtci,rcti))*2;
if(div>1)
{
ans+=(div*2)/3;
}
return ans;
}
else
{
return -1;
}
}
