#include "dna.h"
#include <iostream>
using namespace std;
string A,B;
void init(std::string a, std::string b) {
A=a;
B=b;
}
int get_distance(int x, int y) {
int C1[3]={0,0,0};
int C2[3]={0,0,0};
for(int i=x;i<=y;i++){
if(A[i]=='A')C1[0]++;
if(A[i]=='T')C1[1]++;
if(A[i]=='C')C1[2]++;
if(B[i]=='A')C2[0]++;
if(B[i]=='T')C2[1]++;
if(B[i]=='C')C2[2]++;
}
if(C1[0]!=C2[0]||C1[1]!=C2[1]||C1[2]!=C2[2])return -1;
if(y-x<=2){
if(y-x==0)return 0;
if(y-x==1){
if(A[x]==B[x])return 0;
return 1;
}
if(A[x]==B[x]&&A[x+1]==B[x+1]&&A[y]==B[y])return 0;
if(A[x]==B[x]||A[x+1]==B[x+1]||A[y]==B[y])return 1;
return 2;
}
if(C1[2]==0 && C2[2]==0){
int c=0;
for(int i=x;i<=y;i++){
if(A[i]!=B[i])c++;
}
return c/2;
}
return 0;
}
