//#include "festival.h"
#include<bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC target("avx2")
#define ll long long
#define ld long double
#define pii pair<int,int>
#define pll pair<ll,ll>
#define plx pair<ll,int>
#define f first
#define s second
#define pb push_back
#define all(x) x.begin(),x.end()
#define vi vector<int>
#define vvi vector<vi>
#define ub(x,i) upper_bound(all(x),i)-x.begin()
#define lb(x,i) lower_bound(all(x),i)-x.begin()
#define sz(x) (ll)x.size()
#define cd complex<double>
#define t3 tuple<int,int,int>
using namespace std;
const int mxn=1e5+5,inf=998244353;
int n;
int qs[2][mxn][3]{0},dp[mxn][3][3]{0};
void init(string a, string b){
n=a.size();vector<char>id={'A','C','T'};
for(int i=0;i<n;i++){
qs[0][i+1][0]=qs[0][i][0]+(a[i]=='A');
qs[0][i+1][1]=qs[0][i][1]+(a[i]=='C');
qs[0][i+1][2]=qs[0][i][2]+(a[i]=='T');
qs[1][i+1][0]=qs[1][i][0]+(b[i]=='A');
qs[1][i+1][1]=qs[1][i][1]+(b[i]=='C');
qs[1][i+1][2]=qs[1][i][2]+(b[i]=='T');
for(int j=0;j<3;j++)for(int k=0;k<3;k++){
dp[i+1][j][k]=dp[i][j][k]+(a[i]==id[j]&&b[i]==id[k]);
}
}
}
int get_distance(int x, int y){
x++,y++;bool ch=0;int tt[3][3],cur[3];
for(int i=0;i<3;i++){
if(qs[0][y][i]-qs[0][x-1][i]!=qs[1][y][i]-qs[1][x-1][i])ch=1;
cur[i]=qs[0][y][i]-qs[0][x-1][i];
}if(ch)return -1;
int rs=0;
for(int i=0;i<3;i++)for(int j=0;j<3;j++)tt[i][j]=dp[y][i][j]-dp[x-1][i][j];
cur[0]-=tt[0][0],cur[1]-=tt[1][1],cur[2]-=tt[2][2];
rs+=min(tt[0][1],tt[1][0]),rs+=min(tt[0][2],tt[2][0]),rs+=min(tt[1][2],tt[2][1]);
cur[0]-=min(tt[0][1],tt[1][0])+min(tt[0][2],tt[2][0]);
rs+=2*cur[0];
return rs;
}
/*int main(){
init("ATACAT", "ACTATA");
cout<<get_distance(1, 3);
}*/
