#include "dna.h"
#include "bits/stdc++.h"
using namespace std;
const int N = 1e5 + 5;
int AT[N], AC[N];
int CA[N], CT[N];
int TA[N], TC[N];
int pA[N], qA[N];
int pC[N], qC[N];
int pT[N], qT[N];
int n;
void init(string p, string q) {
int n = p.size();
p = " " + p;
q = " " + q;
for (int i = 1; i <= n; i++) {
AT[i] = AT[i - 1] + (p[i] == 'A' and q[i] == 'T');
AC[i] = AC[i - 1] + (p[i] == 'A' and q[i] == 'C');
CA[i] = CA[i - 1] + (p[i] == 'C' and q[i] == 'A');
CT[i] = CT[i - 1] + (p[i] == 'C' and q[i] == 'T');
TA[i] = TA[i - 1] + (p[i] == 'T' and q[i] == 'A');
TC[i] = TC[i - 1] + (p[i] == 'T' and q[i] == 'C');
pA[i] = pA[i - 1] + (p[i] == 'A');
pC[i] = pC[i - 1] + (p[i] == 'C');
pT[i] = pT[i - 1] + (p[i] == 'T');
qA[i] = qA[i - 1] + (q[i] == 'A');
qC[i] = qC[i - 1] + (q[i] == 'C');
qT[i] = qT[i - 1] + (q[i] == 'T');
}
}
int get_distance(int x, int y) {
x++, y++;
if (pA[y] - pA[x - 1] != qA[y] - qA[x - 1] ||
pC[y] - pC[x - 1] != qC[y] - qC[x - 1] ||
pT[y] - pT[x - 1] != qT[y] - qT[x - 1]) {
return -1;
}
int at = AT[y] - AT[x - 1], ac = AC[y] - AC[x - 1];
int ca = CA[y] - CA[x - 1], ct = CT[y] - CT[x - 1];
int ta = TA[y] - TA[x - 1], tc = TC[y] - TC[x - 1];
int ans = 0;
int atta = min(at, ta);
ans += atta;
at -= atta;
ta -= atta;
int acca = min(ac, ca);
ans += acca;
ac -= acca;
ca -= acca;
int cttc = min(ct, tc);
ans += cttc;
ct -= cttc;
tc -= cttc;
if (!(at == tc && tc == ca) || !(ac == ta && ta == ct)) {
return -1;
}
ans += 2 * at;
ans += 2 * ac;
return ans;
}
