#include "dna.h"
#include <bits/stdc++.h>
#define ll long long int
using namespace std;
string a, b; int n;
vector<ll> as[3], bs[3];
// [0] = A, [1] = T, [2] = C
vector<int> at;
void atupd(int v, int tl, int tr, int pos, int val) {
if (tl == tr) {at[v] = val; return;}
int tm = (tl + tr) / 2;
if (pos <= tm) atupd(2*v, tl, tm, pos, val);
else atupd(2*v+1, tm+1, tr, pos, val);
at[v] = at[2*v] + at[2*v+1];
}
ll atquery(int v, int tl, int tr, int l, int r) {
if (l > r) return 0;
if (l == tl && r == tr) return at[v];
int tm = (tl + tr) / 2;
ll lf = atquery(2*v, tl, tm, l, min(tm, r));
ll rg = atquery(2*v+1, tm+1, tr, max(tm+1, l), r);
return lf + rg;
}
vector<int> ta;
void taupd(int v, int tl, int tr, int pos, int val) {
if (tl == tr) {ta[v] = val; return;}
int tm = (tl + tr) / 2;
if (pos <= tm) taupd(2*v, tl, tm, pos, val);
else taupd(2*v+1, tm+1, tr, pos, val);
ta[v] = ta[2*v] + ta[2*v+1];
}
ll taquery(int v, int tl, int tr, int l, int r) {
if (l > r) return 0;
if (l == tl && r == tr) return ta[v];
int tm = (tl + tr) / 2;
ll lf = taquery(2*v, tl, tm, l, min(tm, r));
ll rg = taquery(2*v+1, tm+1, tr, max(tm+1, l), r);
return lf + rg;
}
vector<int> tc;
void tcupd(int v, int tl, int tr, int pos, int val) {
if (tl == tr) {tc[v] = val; return;}
int tm = (tl + tr) / 2;
if (pos <= tm) tcupd(2*v, tl, tm, pos, val);
else tcupd(2*v+1, tm+1, tr, pos, val);
tc[v] = tc[2*v] + tc[2*v+1];
}
ll tcquery(int v, int tl, int tr, int l, int r) {
if (l > r) return 0;
if (l == tl && r == tr) return tc[v];
int tm = (tl + tr) / 2;
ll lf = tcquery(2*v, tl, tm, l, min(tm, r));
ll rg = tcquery(2*v+1, tm+1, tr, max(tm+1, l), r);
return lf + rg;
}
vector<int> ct;
void ctupd(int v, int tl, int tr, int pos, int val) {
if (tl == tr) {ct[v] = val; return;}
int tm = (tl + tr) / 2;
if (pos <= tm) ctupd(2*v, tl, tm, pos, val);
else ctupd(2*v+1, tm+1, tr, pos, val);
ct[v] = ct[2*v] + ct[2*v+1];
}
ll ctquery(int v, int tl, int tr, int l, int r) {
if (l > r) return 0;
if (l == tl && r == tr) return ct[v];
int tm = (tl + tr) / 2;
ll lf = ctquery(2*v, tl, tm, l, min(tm, r));
ll rg = ctquery(2*v+1, tm+1, tr, max(tm+1, l), r);
return lf + rg;
}
vector<int> ca;
void caupd(int v, int tl, int tr, int pos, int val) {
if (tl == tr) {ca[v] = val; return;}
int tm = (tl + tr) / 2;
if (pos <= tm) caupd(2*v, tl, tm, pos, val);
else caupd(2*v+1, tm+1, tr, pos, val);
ca[v] = ca[2*v] + ca[2*v+1];
}
ll caquery(int v, int tl, int tr, int l, int r) {
if (l > r) return 0;
if (l == tl && r == tr) return ca[v];
int tm = (tl + tr) / 2;
ll lf = caquery(2*v, tl, tm, l, min(tm, r));
ll rg = caquery(2*v+1, tm+1, tr, max(tm+1, l), r);
return lf + rg;
}
vector<int> ac;
void acupd(int v, int tl, int tr, int pos, int val) {
if (tl == tr) {ac[v] = val; return;}
int tm = (tl + tr) / 2;
if (pos <= tm) acupd(2*v, tl, tm, pos, val);
else acupd(2*v+1, tm+1, tr, pos, val);
ac[v] = ac[2*v] + ac[2*v+1];
}
ll acquery(int v, int tl, int tr, int l, int r) {
if (l > r) return 0;
if (l == tl && r == tr) return ac[v];
int tm = (tl + tr) / 2;
ll lf = acquery(2*v, tl, tm, l, min(tm, r));
ll rg = acquery(2*v+1, tm+1, tr, max(tm+1, l), r);
return lf + rg;
}
int get_distance(int x, int y) {
for (int i = 0; i < 3; i++) {
ll suma = as[i][y], sumb = bs[i][y];
if (x > 0) {
suma -= as[i][x-1];
sumb -= bs[i][x-1];
}
if (suma != sumb) return -1;
}
int at[2] = { }, tc[2] = { }, ca[2] = { };
at[0] = atquery(1, 1, (1LL << 17), x+1, y+1);
at[1] = taquery(1, 1, (1LL << 17), x+1, y+1);
tc[0] = tcquery(1, 1, (1LL << 17), x+1, y+1);
tc[1] = ctquery(1, 1, (1LL << 17), x+1, y+1);
ca[0] = caquery(1, 1, (1LL << 17), x+1, y+1);
ca[1] = acquery(1, 1, (1LL << 17), x+1, y+1);
int cnt = 0;
if (at[0] > at[1]) {
cnt += at[1];
at[0] -= at[1];
at[1] = 0;
} else {
cnt += at[0];
at[1] -= at[0];
at[0] = 0;
}
if (tc[0] > tc[1]) {
cnt += tc[1];
tc[0] -= tc[1];
tc[1] = 0;
} else {
cnt += tc[0];
tc[1] -= tc[0];
tc[0] = 0;
}
if (ca[0] > ca[1]) {
cnt += ca[1];
ca[0] -= ca[1];
ca[1] = 0;
} else {
cnt += ca[0];
ca[1] -= ca[0];
ca[0] = 0;
}
cnt += (2*(at[0]+at[1]+tc[0]+tc[1]+ca[0]+ca[1]))/3;
return cnt;
}
// int main() {
// string aa, bb; cin >> aa >> bb;
void init(string aa, string bb) {
a = aa; b = bb; n = a.size();
for (int i = 0; i < 3; i++) {
as[i].resize(n); bs[i].resize(n);
}
if (a[0] == 'A') as[0][0]++;
if (b[0] == 'A') bs[0][0]++;
if (a[0] == 'T') as[1][0]++;
if (b[0] == 'T') bs[1][0]++;
if (a[0] == 'C') as[2][0]++;
if (b[0] == 'C') bs[2][0]++;
for (int i = 1; i < n; i++) {
for (int j = 0; j < 3; j++) {
as[j][i] = as[j][i-1];
bs[j][i] = bs[j][i-1];
}
if (a[i] == 'A') as[0][i]++;
if (b[i] == 'A') bs[0][i]++;
if (a[i] == 'T') as[1][i]++;
if (b[i] == 'T') bs[1][i]++;
if (a[i] == 'C') as[2][i]++;
if (b[i] == 'C') bs[2][i]++;
}
at.assign((1LL << 18), 0LL);
ta.assign((1LL << 18), 0LL);
tc.assign((1LL << 18), 0LL);
ct.assign((1LL << 18), 0LL);
ca.assign((1LL << 18), 0LL);
ac.assign((1LL << 18), 0LL);
for (int i = 0; i < n; i++) {
if (a[i] == 'A' && b[i] == 'T') {
atupd(1, 1, (1LL << 17), i+1, 1);
}
if (a[i] == 'T' && b[i] == 'C') {
tcupd(1, 1, (1LL << 17), i+1, 1);
}
if (a[i] == 'C' && b[i] == 'A') {
caupd(1, 1, (1LL << 17), i+1, 1);
}
if (a[i] == 'T' && b[i] == 'A') {
taupd(1, 1, (1LL << 17), i+1, 1);
}
if (a[i] == 'C' && b[i] == 'T') {
ctupd(1, 1, (1LL << 17), i+1, 1);
}
if (a[i] == 'A' && b[i] == 'C') {
acupd(1, 1, (1LL << 17), i+1, 1);
}
}
}
