#include "dna.h"
#include <bits/stdc++.h>
using namespace std;
int ac[100010], ca[100010], ab[100010], ba[100010], bc[100010], cb[100010], aa[100010], bb[100010], cc[100010];
void init(string a, string b)
{
for(int i=0; i<a.size(); i++)
{
ca[i+1]=ca[i]; ac[i+1]=ac[i]; ba[i+1]=ba[i];
ab[i+1]=ab[i]; cb[i+1]=cb[i]; bc[i+1]=bc[i];
aa[i+1]=aa[i]; bb[i+1]=bb[i]; cc[i+1]=cc[i];
if(a[i]=='A' and b[i]=='T')ab[i+1]++;
if(a[i]=='A' and b[i]=='C')ac[i+1]++;
if(a[i]=='T' and b[i]=='C')bc[i+1]++;
if(a[i]=='C' and b[i]=='T')cb[i+1]++;
if(a[i]=='T' and b[i]=='A')ba[i+1]++;
if(a[i]=='C' and b[i]=='A')ca[i+1]++;
if(a[i]=='A' and b[i]=='A')aa[i+1]++;
if(a[i]=='T' and b[i]=='T')bb[i+1]++;
if(a[i]=='C' and b[i]=='C')cc[i+1]++;
}
}
int calc(int *niz, int x, int y)
{
return niz[y]-niz[x-1];
}
int get_distance(int x, int y)
{
if(calc(ab, x, y)+calc(ac, x, y)!=calc(ba, x, y)+calc(ca, x, y))return -1;
if(calc(ab, x, y)+calc(cb, x, y)!=calc(ba, x, y)+calc(bc, x, y))return -1;
if(calc(bc, x, y)+calc(ac, x, y)!=calc(cb, x, y)+calc(ca, x, y))return -1;
int dist=y-x+1;
dist-=calc(aa, x, y);
dist-=calc(bb, x, y);
dist-=calc(cc, x, y);
int BA=calc(ba, x, y), AB=calc(ab, x, y), BC=calc(bc, x, y), CB=calc(cb, x, y), CA=calc(ca, x, y), AC=calc(ac, x, y);
int cyc1=min(AB, BA);
AB-=cyc1; BA-=cyc1; dist-=cyc1;
int cyc2=min(AC, CA);
AC-=cyc2; CA-=cyc2; dist-=cyc2;
int cyc3=min(BC, CB);
CB-=cyc3; BC-=cyc3; dist-=cyc3;
if(AB!=BC or BC!=CA or CA!=AB)return -1;
else dist-=AB;
if(BA!=AC or AC!=CB or CB!=BA)return -1;
else dist-=BA;
return dist;
}
/*int main()
{
string a, b;
cin>>a>>b;
init(a, b);
int q;cin>>q;
while(q--)
{
int x, y; cin>>x>>y;
cout<<get_distance(x, y)<<endl;
}
}*/
