#include <bits/stdc++.h>
#include "dna.h"
using namespace std;
typedef long long ll;
int n, ac[100001], at[100001], ct[100001];
int a[100001], c[100001], t[100001];
void init(string A, string B)
{
n = A.size();
a[0] = c[0] = t[0] = ac[0] = at[0] = ct[0] = 0;
for (int i = 0; i < n; i++)
{
a[i + 1] = a[i] + (A[i] == 'A') - (B[i] == 'A');
c[i + 1] = c[i] + (A[i] == 'C') - (B[i] == 'C');
t[i + 1] = t[i] + (A[i] == 'T') - (B[i] == 'T');
ac[i + 1] = ac[i], at[i + 1] = at[i], ct[i + 1] = ct[i];
ac[i + 1] += ((A[i] == 'A' && B[i] == 'C') || (A[i] == 'C' && B[i] == 'A'));
at[i + 1] += ((A[i] == 'C' && B[i] == 'T') || (A[i] == 'T' && B[i] == 'C'));
ct[i + 1] += ((A[i] == 'C' && B[i] == 'T') || (A[i] == 'C' && B[i] == 'T'));
ac[i + 1] += ((A[i] == 'T' && B[i] != 'T') || (A[i] != 'T' && B[i] == 'T')) * 2;
at[i + 1] += ((A[i] == 'C' && B[i] != 'C') || (A[i] != 'C' && B[i] == 'C')) * 2;
ct[i + 1] += ((A[i] == 'A' && B[i] != 'A') || (A[i] != 'A' && B[i] == 'A')) * 2;
}
}
int get_distance(int x, int y)
{
if (a[y + 1] - a[x] != 0)
return -1;
if (c[y + 1] - c[x] != 0)
return -1;
if (t[y + 1] - t[x] != 0)
return -1;
return min({ac[y + 1] - ac[x], at[y + 1] - at[x], ct[y + 1] - ct[y]}) / 2;
}
