#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "debug.h"
#else
#define dbg(...) 42
#endif
string a, b;
vector<int> P;
vector<vector<int>> A, B;
void init(string s, string t) {
a = s;
b = t;
int n = a.size();
P.resize(n + 1);
A.resize(n + 1, vector<int>(3));
B.resize(n + 1, vector<int>(3));
for (int i = 0; i < n; i++) {
A[i + 1][0] = A[i][0] + (a[i] == 'A');
A[i + 1][1] = A[i][1] + (a[i] == 'T');
A[i + 1][2] = A[i][2] + (a[i] == 'C');
B[i + 1][0] = B[i][0] + (b[i] == 'A');
B[i + 1][1] = B[i][1] + (b[i] == 'T');
B[i + 1][2] = B[i][2] + (b[i] == 'C');
P[i + 1] = P[i] + (a[i] == b[i]);
}
}
int get_distance(int l, int r) {
for (int i = 0; i < 3; i++) {
int x = A[r + 1][i] - A[l][i];
int y = B[r + 1][i] - B[l][i];
if (x != y) {
return -1;
}
}
return r - l - (P[r + 1] - P[l]);
}
