#include <bits/stdc++.h>
#include "dna.h"
using namespace std;
const int mxN = 2e5 + 1000;
string A, B;
int dp[mxN][3];
void init(string a, string b){
A = a, B = b;
memset(dp, 0, sizeof(dp));
for(int i = 1; i <= (int) A.size(); ++i){
dp[i][0] = dp[i - 1][0];
dp[i][1] = dp[i - 1][1];
dp[i][2] = dp[i - 1][2];
dp[i][0] += a[i - 1] == 'A';
dp[i][0] -= b[i - 1] == 'A';
dp[i][1] += a[i - 1] == 'T';
dp[i][1] -= b[i - 1] == 'T';
dp[i][2] += a[i - 1] != b[i - 1];
}
}
int get_distance(int x, int y){
++y, ++x;
if(dp[y][0] - dp[x - 1][0] == 0 && dp[y][1] - dp[x - 1][1] == 0) return (dp[y][2] - dp[x - 1][2]) / 2;
return -1;
}
/*int main(){
#ifndef ONLINE_JUDGE
freopen("inp.in", "r", stdin);
freopen("output.out", "w", stdout);
#endif
ios_base::sync_with_stdio(0);
cin.tie(nullptr); cout.tie(nullptr);
return 0;
}*/
