#include "dna.h"
int C[3][3][100001];
void init(std::string a, std::string b) {
int n = a.size();
for (int i = 0; i < n; i++)
{
for (int x = 0; x < 3; x++)
for (int y = 0; y < 3; y++)
C[x][y][i + 1] = C[x][y][i];
int c1 = 0;
int c2 = 0;
if (a[i] == 'A')
c1 = 1;
if (a[i] == 'T')
c1 = 2;
if (b[i] == 'A')
c2 = 1;
if (b[i] == 'T')
c2 = 2;
C[c1][c2][i + 1]++;
}
}
#include <bits/stdc++.h>
using namespace std;
int get_distance(int x, int y) {
int A[3][3];
for (int a = 0; a < 3; a++)
{
for (int b = 0; b < 3; b++)
{
A[a][b] = C[a][b][y + 1] - C[a][b][x];
}
}
for (int a = 0; a < 3; a++)
{
int bal = 0;
for (int b = 0; b < 3; b++)
{
bal += A[a][b];
bal -= A[b][a];
}
if (bal != 0)
return -1;
}
int ans = 0;
bool ok = true;
while (ok)
{
ok = false;
for (int x : {0, 1, 2})
{
for (int y : {0, 1, 2})
{
if (x == y)
continue;
int c = min({A[x][y], A[y][x]});
A[x][y] -= c;
A[y][x] -= c;
ans += c;
if (c != 0)
ok = true;
}
}
for (int x : {0, 1, 2})
{
for (int y : {0, 1, 2})
{
if (x == y)
continue;
int z = 3 - x - y;
int c = min({A[x][y], A[y][z], A[z][x]});
A[x][y] -= c;
A[y][z] -= c;
A[z][x] -= c;
ans += 2 * c;
if (c != 0)
ok = true;
}
}
}
return ans;
}
