#include "dna.h"
#include<iostream>
#include<vector>
#include<set>
#include<map>
#include<numeric>
#include<string>
#include<stack>
#include<queue>
#include<string.h>
#include<array>
#include<climits>
#include<algorithm>
#include<cmath>
using namespace std;
#define ff first
#define ss second
#define endl '\n'
const int inf = 1e9;
string s, s1;
void init(string a, string b){
s = a;
s1 = b;
return;
}
int get_distance(int x, int y){
map<char, int> mp, mp1;
bool is = 1;
for(int i = x; i <= y; i++){
mp[s[i]] += 1;
mp1[s1[i]] += 1;
}
for(auto t : mp){
if(mp[t.ff] != mp1[t.ff]){
is = 0;
}
}
int res = 0;
for(int i = x; i <= y; i++){
if(s[i] != s1[i]){
res += 1;
}
}
if(!is){
return -1;
}
else{
return res / 2;
}
}
// signed main(){
// string a, b;
// cin >> a >> b;
// init(a, b);
// cout << get_distance(3, 5);
// }
