#include "dna.h"
#include <map>
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int const N=1e5+10;
int pre[2][3][N]={};
int n;
int dif[3][3][N]={};
map<char,int>d;
void init(string a,string b)
{
d['A']=0;d['C']=1;d['T']=2;
n=a.size();
for (int i=0;i<n;i++)
{
for (int j=0;j<3;j++)
pre[0][j][i+1]=pre[0][j][i];
pre[0][d[a[i]]][i+1]++;
}
for (int i=0;i<n;i++)
{
for (int j=0;j<3;j++)
pre[1][j][i+1]=pre[1][j][i];
pre[1][d[b[i]]][i+1]++;
}
for (int i=0;i<n;i++)
{
for (int j=0;j<3;j++)
for (int k=0;k<3;k++)
dif[j][k][i+1]=dif[j][k][i];
dif[d[a[i]]][d[b[i]]][i+1]++;
}
}
int get_distance(int x, int y)
{
y++;
for (int i=0;i<3;i++)
{
if (pre[0][i][y]-pre[0][i][x]!=pre[1][i][y]-pre[1][i][x])
{
return -1;
}
}
int pr[3][3]={};
for (int i=0;i<3;i++)
for (int j=0;j<3;j++)
pr[i][j]=dif[i][j][y]-dif[i][j][x];
int ans=0;
vector<int>z;
z.push_back(pr[1][2]);z.push_back(pr[0][1]);z.push_back(pr[2][0]);
sort(z.begin(), z.end());
ans+=2*z[0];
z={pr[0][2],pr[2][1],pr[1][0]};
sort(z.begin(), z.end());
ans+=2*z[0];
return ans;
}
