#include <bits/stdc++.h>
using namespace std;
int N;
string A1, B;
vector<tuple<int, int, int>> cntA(100001, make_tuple(0, 0, 0));
vector<tuple<int, int, int>> cntB(100001, make_tuple(0, 0, 0));
vector<int> A(100001);
// 0 = A, 1 = T, 2 = C
int get_distance(int x, int y){
if(x == 0 and cntA[y] != cntB[y]) return -1;
if(get<0>(cntA[y]) - get<0>(cntA[x - 1]) != get<0>(cntB[y]) - get<0>(cntB[x - 1]) or get<1>(cntA[y]) - get<1>(cntA[x - 1]) != get<1>(cntB[y]) - get<1>(cntB[x - 1]) or get<2>(cntA[y]) - get<2>(cntA[x - 1]) != get<2>(cntB[y]) - get<2>(cntB[x - 1])){
return -1;
}
if(x == 0){
if(A[y] != 0) return A[y] - (A[y]/2);
else return 0;
}
if(A[y] - A[x - 1] != 0) return A[y] - A[x - 1] - ((A[y] - A[x - 1])/2);
else return 0;
}
void init(string a, string b){
A1 = a;
B = b;
N = a.size();
for(int i = 0; i < N; i++){
if(i != 0) cntA[i] = cntA[i - 1];
if(a[i] == 'A') get<0>(cntA[i])++;
else if(a[i] == 'T') get<1>(cntA[i])++;
else get<2>(cntA[i])++;
}
for(int i = 0; i < N; i++){
if(i != 0) cntB[i] = cntB[i - 1];
if(b[i] == 'A') get<0>(cntB[i])++;
else if(b[i] == 'T') get<1>(cntB[i])++;
else get<2>(cntB[i])++;
}
if(a[0] != b[0]) A[0] = 1;
else A[0] = 0;
for(int i = 1; i < N; i++){
A[i] = A[i - 1];
if(a[i] != b[i]) A[i]++;
}
}
