#include "dna.h"
#include<bits/stdc++.h>
using namespace std;
string s1, s2;
void init(std::string a, std::string b) {
s1 = a;s2 = b;
}
int get_distance(int x, int y) {
int count = 0;
string NewNewS1 = s1.substr(x,y);
string NewNewS2 = s2.substr(x,y);
string NewS1 = NewNewS1;
string NewS2 = NewNewS2;
sort(NewNewS1.begin(),NewNewS1.end());
sort(NewNewS2.begin(),NewNewS2.end());
if(NewNewS1 != NewNewS2){
return -1;
}
else{
for(int i = x - 1;i <= y;i++){
if(NewS1[i] != NewS2[i]){
count++;
}
}
return (count+1)/2;
}
return 0;
}
