#include "dna.h"
#include <iostream>
#include <complex>
#include <vector>
#include <string>
#include <algorithm>
#include <cstdio>
#include <numeric>
#include <cstring>
#include <ctime>
#include <cstdlib>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <list>
#include <cmath>
#include <bitset>
#include <cassert>
#include <queue>
#include <stack>
#include <deque>
#include <random>
using namespace std;
template<typename T1, typename T2> inline void chkmin(T1 &a, T2 b) {if (a > b) a = b;}
template<typename T1, typename T2> inline void chkmax(T1 &a, T2 b) {if (a < b) a = b;}
#define files(FILENAME) read(FILENAME); write(FILENAME)
#define read(FILENAME) freopen((FILENAME + ".in").c_str(), "r", stdin)
#define write(FILENAME) freopen((FILENAME + ".out").c_str(), "w", stdout)
#define all(c) (c).begin(), (c).end()
#define sz(c) (int)(c).size()
#define left left228
#define right right228
#define y1 y1228
#define mp make_pair
#define pb push_back
#define y2 y2228
#define rank rank228
using ll = long long;
using ld = long double;
const string FILENAME = "input";
const int MAXN = 100228;
int cntA[MAXN][26], cntB[MAXN][26];
int diff[MAXN];
void init(string a, string b) {
int n = sz(a);
for (int i = 1; i <= n; i++) {
for (int j = 0; j < 26; j++) {
cntA[i][j] = cntA[i - 1][j];
}
cntA[i][a[i - 1] - 'a']++;
}
for (int i = 1; i <= n; i++) {
for (int j = 0; j < 26; j++) {
cntB[i][j] = cntB[i - 1][j];
}
cntB[i][b[i - 1] - 'a']++;
}
for (int i = 1; i <= n; i++) {
diff[i] = diff[i - 1] + (a[i - 1] != b[i - 1]);
}
}
int get_distance(int l, int r) {
for (int j = 0; j < 26; j++) {
if (cntA[r][j] - cntA[l - 1][j] != cntB[r][j] - cntB[l - 1][j]) {
return -1;
}
}
int x = diff[r] - diff[l - 1];
return (x + 1) / 2;
}
/**
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
//read(FILENAME);
return 0;
}
**/
