#include "dna.h"
#include <bits/stdc++.h>
using namespace std;
string a,b;
void init(string f, string s) {
a=f;b=s;
}
int get_distance(int x, int y) {
if(x==y and a[x]==b[x])return 0;
if(x==y and a[x]!=b[x])return -1;
if(y-x==1 and a[x]==b[x] and a[y]==b[y])return 0;
if(y-x==1 and a[x]==b[y] and a[y]==b[x])return 1;
if(y-x==1)return -1;
int c=0;
map<char,int> mp;
for(int i=x;i<=y;i++){
if(a[i]==b[i])++c;
}
for(int i=x;i<=y;i++){
mp[a[i]]++;
}
for(int i=x;i<=y;i++){
mp[b[i]]--;
}
for(int i=x;i<=y;i++){
if(mp[a[i]]!=0)return -1;
}
if(c==0)return 2;
if(c==1)return 1;
if(c==3)return 0;
return -1;
}
