#include <bits/stdc++.h>
#include "dna.h"
using namespace std;
const int N = 1e5 + 1;
int at[N] , ta[N] , ac[N] , ca[N] , tc[N] , ct[N];
void init(string a, string b) {
int n = a.size();
a = ' ' + a;
b = ' ' + b;
for (int i=1;i<=n;i++) {
at[i] = at[i-1] + (a[i]=='A' && b[i]=='T');
ta[i] = ta[i-1] + (a[i]=='T' && b[i]=='A');
ac[i] = ac[i-1] + (a[i]=='A' && b[i]=='C');
ca[i] = ca[i-1] + (a[i]=='C' && b[i]=='A');
tc[i] = tc[i-1] + (a[i]=='T' && b[i]=='C');
ct[i] = ct[i-1] + (a[i]=='C' && b[i]=='T');
}
}
int get_distance(int x, int y) {
x++;
y++;
int nowat = at[y] - at[x-1];
int nowta = ta[y] - ta[x-1];
int nowac = ac[y] - ac[x-1];
int nowca = ca[y] - ca[x-1];
int nowtc = tc[y] - tc[x-1];
int nowct = ct[y] - ct[x-1];
int minat = min(nowat, nowta);
int minac = min(nowac, nowca);
int mintc = min(nowtc, nowct);
nowat -= minat;
nowta -= minat;
nowac -= minac;
nowca -= minac;
nowtc -= mintc;
nowct -= mintc;
if (nowat==nowtc && nowtc==nowca && nowct==nowta && nowta==nowac) return minat + minac + mintc + max(nowat, nowta) * 2;
else return -1;
return 0;
}
