#include "dna.h"
#include<bits/stdc++.h>
using namespace std;
int a[100004][3][3];
void init(string A, string B) {
int n = A.size();
for (int i = 0; i < n; i ++) {
if ( A[i] == 'T') A[i] = 'B';
if ( B[i] == 'T') B[i] = 'B';
A[i] += 32;
B[i] += 32;
for (int j = 0; j <= 2; j ++) {
for (int r = 0; r <= 2; r ++) {
if ( i == 0) a[i][j][r] = 0;
else a[i][j][r] = a[i - 1][j][r];
}
}
int x = A[i] - 'a';
int y = B[i] - 'a';
a[i][x][y] ++;
}
}
int cnt(int l, int r, int x, int y){
int s= a[r][x][y];
if ( l == 0) return s;
s -= (a[l - 1][x][y]);
return s;
}
int get_distance(int x, int y) {
int ans = 0;
int ab = cnt(x, y, 0, 1), ba = cnt(x, y, 1, 0), ac = cnt(x, y, 0, 2), ca = cnt(x, y, 2, 0), bc = cnt(x, y, 1, 2), cb = cnt(x, y, 2, 1);
x = min(ab, ba);
ans += x;
ab -= x;
ba -= x;
x = min(ac, ca);
ans += x;
ac -= x;
ca -= x;
x = min(bc, cb);
ans += x;
bc -= x;
cb -= x;
if ( ab == 0 && ba == 0 && ca == 0 && ac == 0 && bc == 0 && cb == 0) return ans;
if ( (ab == 0 || bc == 0 || ca == 0) && (ba == 0 || ac == 0 || cb == 0)) return -1;
ab += ba;
bc += cb;
ac += ca;
int s = ab + bc + ac;
if ( ac != ab || ac != bc || ab != bc) return -1;
return ans + s - max(ab, max(bc, ac));
}
