#include <bits/stdc++.h>
//#include </home/igor/cpp-dump/cpp-dump.hpp>
#define pb push_back
#define ll long long
using namespace std;
// A => 0
// C => 1
// T => 2
bool gc;
vector<int> A, B;
typedef vector<array<int, 3>> pref;
vector<pref> pref_tbl;
void init(string a, string b)
{
gc = true;
// cerr << "A\n";
// adder.clear();
// A C T
pref adder = {{0, 0, 0},
{0, 0, 0},
{0, 0, 0}};
pref_tbl.clear();
int abc[3];
for (int i = 0; i < a.size(); i++)
{
if (b[i] == 'A')
{
B.pb(0);
abc[0]++;
}
else if (b[i] == 'C')
{
B.pb(1);
abc[1]++;
}
else if (b[i] == 'T')
{
B.pb(2);
abc[2]++;
}
}
// cerr << "B\n";
pref_tbl.pb(adder);
for (int i = 0; i < b.size(); i++)
{
// cpp_dump(adder);
// cpp_dump(pref_tbl);
if (a[i] == 'A')
{
A.pb(0);
abc[0]--;
if (b[i] == 'C')
adder[0][1]++;
if (b[i] == 'T')
adder[0][2]++;
}
else if (a[i] == 'C')
{
A.pb(1);
abc[1]--;
if (b[i] == 'A')
adder[1][0]++;
if (b[i] == 'T')
adder[1][2]++;
}
else if (a[i] == 'T')
{
A.pb(2);
abc[2]--;
if (b[i] == 'A')
adder[2][0]++;
if (b[i] == 'C')
adder[2][1]++;
}
pref_tbl.pb(adder);
}
// cerr << "C\n";
if (abc[0] != 0 || abc[1] != 0 || abc[2] != 0)
gc = false;
}
int get_distance(int x, int y)
{
// cerr << "D\n";
if (!gc)
return -1;
// cpp_dump(pref_tbl);
int ans = 0;
pref curr = pref_tbl[y + 1];
// cerr << "D'\n";
curr[0][1] -= pref_tbl[x][0][1];
curr[0][2] -= pref_tbl[x][0][2];
// cerr << "D''\n";
curr[1][0] -= pref_tbl[x][1][0];
curr[1][2] -= pref_tbl[x][1][2];
// cerr << "D'''\n";
curr[2][0] -= pref_tbl[x][2][0];
curr[2][1] -= pref_tbl[x][2][1];
// cerr << "E\n";
for (int i = x; i <= y; i++)
{
// cerr << "F\n";
// cpp_dump(curr);
// cpp_dump(i, A[i], B[i]);
// cpp_dump(curr[A[i]][B[i]], curr[B[i]][A[i]]);
if (A[i] == B[i])
continue;
if (curr[A[i]][B[i]] == 0 && curr[B[i]][A[i]] == 0) // oba już zamienione
continue;
if (curr[A[i]][B[i]] > 0 && curr[B[i]][A[i]] > 0) // oba możemy zamienić miejscami
{
ans++;
curr[A[i]][B[i]]--;
curr[B[i]][A[i]]--;
continue;
}
int trzeci;
if (A[i] != 0 && B[i] != 0)
trzeci = 0;
else if (A[i] != 1 && B[i] != 1)
trzeci = 1;
else if (A[i] != 2 && B[i] != 2)
trzeci = 2;
if (curr[A[i]][B[i]] > 0) // A na B ale nie B na A
{
curr[A[i]][trzeci]++;
curr[A[i]][B[i]]--;
curr[B[i]][trzeci]--;
ans++;
continue;
}
else if (curr[A[i]][B[i]] > 0) // A na B ale nie B na A
{
curr[B[i]][trzeci]++;
curr[B[i]][A[i]]--;
curr[A[i]][trzeci]--;
ans++;
continue;
}
else
cerr << "error0\n";
}
// cerr << "G\n";
return ans;
}
