#include <bits/stdc++.h>
#include "dna.h"
using namespace std;
#define N 100005
vector<int> a(N),b(N),c(N),d(N),e(N),f(N);
void init(string a, string b){
int n=a.size();
for(int i=0;i<n;i++){
if(a[i]=='A' && b[i]=='C') a[i+1]=a[i]+1;
else if(a[i]=='A' && b[i]=='T') b[i+1]=b[i]+1;
else if(a[i]=='C' && b[i]=='A') c[i+1]=c[i]+1;
else if(a[i]=='C' && b[i]=='T') d[i+1]=d[i]+1;
else if(a[i]=='T' && b[i]=='A') e[i+1]=e[i]+1;
else if(a[i]=='T' && b[i]=='C') f[i+1]=f[i]+1;
}
}
int get_distance(int x, int y){
y++;
int A=a[y]-a[x];
int B=b[y]-b[x];
int C=c[y]-c[x];
int D=d[y]-d[x];
int E=e[y]-e[x];
int F=f[y]-f[x];
if (E!=A+B-C || F!=C+D-A)
return -1;
return B+D+max(A, C);
}
