#include <bits/stdc++.h>
#include <cstdio>
#include <cassert>
#include <string>
#include <vector>
using namespace std;
const int MX = 1e5+5;
int contA1[MX], contC1[MX], contT1[MX];
int contA2[MX], contC2[MX], contT2[MX];
int AC[MX], AT[MX], CA[MX], CT[MX], TA[MX], TC[MX];
#define FOR(i, a, b) for(int i = (a); i < (b); ++i)
#define F0R(i, b) FOR(i, 0, b)
#define sz(v) (int)(v).size()
void init(std::string a, std::string b) {
FOR(i, 1, sz(a)+1){
contA1[i] = contA1[i-1] + (a[i-1] == 'A');
contC1[i] = contC1[i-1] + (a[i-1] == 'C');
contT1[i] = contT1[i-1] + (a[i-1] == 'T');
}
FOR(i, 1, sz(b)+1){
contA2[i] = contA2[i-1] + (b[i-1] == 'A');
contC2[i] = contC2[i-1] + (b[i-1] == 'C');
contT2[i] = contT2[i-1] + (b[i-1] == 'T');
}
FOR(i, 1, sz(a)+1){
AC[i] = AC[i-1] + (a[i-1] == 'A' && b[i-1] == 'C');
AT[i] = AT[i-1] + (a[i-1] == 'A' && b[i-1] == 'T');
CA[i] = CA[i-1] + (a[i-1] == 'C' && b[i-1] == 'A');
CT[i] = CT[i-1] + (a[i-1] == 'C' && b[i-1] == 'T');
TA[i] = TA[i-1] + (a[i-1] == 'T' && b[i-1] == 'A');
TC[i] = TC[i-1] + (a[i-1] == 'T' && b[i-1] == 'C');
}
}
int get_distance(int x, int y) {
if(contA1[y+1] - contA1[x] != contA2[y+1] - contA2[x]) return -1;
if(contC1[y+1] - contC1[x] != contC2[y+1] - contC2[x]) return -1;
if(contT1[y+1] - contT1[x] != contT2[y+1] - contT2[x]) return -1;
int ret = 0;
// cycles of size two
// AC-CA
if(min(AC[y+1] - AC[x], CA[y+1] - CA[x]) > 0){
ret += 2 * min(AC[y+1] - AC[x], CA[y+1] - CA[x]) - 1;
}
// AT-TA
if(min(AT[y+1] - AT[x], TA[y+1] - TA[x]) > 0){
ret += 2 * min(AT[y+1] - AT[x], TA[y+1] - TA[x]) - 1;
}
// CT-TC
if(min(CT[y+1] - CT[x], TC[y+1] - TC[x]) > 0){
ret += 2 * min(CT[y+1] - CT[x], TC[y+1] - TC[x]) - 1;
}
// cycles of size three
if(min({AC[y+1] - AC[x], CT[y+1] - CT[x], TA[y+1] - TA[x]}) > 0){
ret += 3 * min({AC[y+1] - AC[x], CT[y+1] - CT[x], TA[y+1] - TA[x]}) - 1;
}
if(min({AT[y+1] - AT[x], TC[y+1] - TC[x], CA[y+1] - CA[x]}) > 0){
ret += 3 * min({AT[y+1] - AT[x], TC[y+1] - TC[x], CA[y+1] - CA[x]}) - 1;
}
return ret;
}
