#include <bits/stdc++.h>
#include "dna.h"
using namespace std;
int n;
int ab[100005],ba[100005],ac[100005],ca[100005],bc[100005],cb[100005];
int spa[3][100005],spb[3][100005];
void init(string a, string b)
{
n = a.size();
a = ' ' + a;
b = ' ' + b;
for (int i = 1; i <= n; i++)
{
if (a[i] == 'T')
a[i] = 'b';
if (b[i] == 'T')
b[i] = 'b';
if (a[i] == 'A')
a[i] = 'a';
if (b[i] == 'A')
b[i] = 'a';
if (a[i] == 'C')
a[i] = 'c';
if (b[i] == 'C')
b[i] = 'c';
}
for (int i = 1; i <= n; i++)
{
for (int j = 0; j < 3; j++)
spa[j][i] = spa[j][i - 1],spb[j][i] = spb[j][i - 1];
spa[a[i] - 'a'][i]++;
spb[b[i] - 'a'][i]++;
ab[i] = ab[i - 1];
ba[i] = ba[i - 1];
ac[i] = ac[i - 1];
ca[i] = ca[i - 1];
bc[i] = bc[i - 1];
cb[i] = cb[i - 1];
if (a[i] == 'a' and b[i] == 'b')
ab[i]++;
if (a[i] == 'b' and b[i] == 'a')
ba[i]++;
if (a[i] == 'a' and b[i] == 'c')
ac[i]++;
if (a[i] == 'c' and b[i] == 'a')
ca[i]++;
if (a[i] == 'b' and b[i] == 'c')
bc[i]++;
if (a[i] == 'c' and b[i] == 'b')
cb[i]++;
}
}
int get_distance(int x,int y)
{
x++;
y++;
for (int j = 0; j < 3; j++)
if (spa[j][y] - spa[j][x - 1] != spb[j][y] - spb[j][x - 1])
return -1;
int ans = min(ab[y] - ab[x - 1],ba[y] - ba[x - 1]) + min(ac[y] - ac[x - 1],ca[y] - ca[x - 1]) + min(bc[y] - bc[x - 1],cb[y] - cb[x - 1]);
ans += 2 * (max(ab[y] - ab[x - 1],ba[y] - ba[x - 1]) - min(ab[y] - ab[x - 1],ba[y] - ba[x - 1]));
return ans;
}
