#include "dna.h"
#include<bits/stdc++.h>
using namespace std;
int n;
string A;
string B;
vector<int> prefDA;
vector<int> prefDC;
vector<int> prefDT;
vector<int> prefBA;
vector<int> prefBC;
vector<int> prefBT;
vector<int> prefAC;
vector<int> prefCA;
vector<int> prefAT;
vector<int> prefTA;
vector<int> prefCT;
vector<int> prefTC;
void init(string a, string b){
n = (int)a.size();
A = a;
B = b;
prefDA.resize(n);
prefDC.resize(n);
prefDT.resize(n);
prefBA.resize(n);
prefBC.resize(n);
prefBT.resize(n);
prefAC.resize(n);
prefCA.resize(n);
prefAT.resize(n);
prefTA.resize(n);
prefCT.resize(n);
prefTC.resize(n);
for(int i = 0; i < n; i++){
if(i != 0){
prefDA[i] = prefDA[i - 1];
prefDC[i] = prefDC[i - 1];
prefDT[i] = prefDT[i - 1];
prefBA[i] = prefBA[i - 1];
prefBC[i] = prefBC[i - 1];
prefBT[i] = prefBT[i - 1];
prefAC[i] = prefAC[i - 1];
prefCA[i] = prefCA[i - 1];
prefAT[i] = prefAT[i - 1];
prefTA[i] = prefTA[i - 1];
prefCT[i] = prefCT[i - 1];
prefTC[i] = prefTC[i - 1];
}
if(A[i] == 'A'){
prefDA[i]++;
}
if(A[i] == 'C'){
prefDC[i]++;
}
if(A[i] == 'T'){
prefDT[i]++;
}
if(B[i] == 'A'){
prefBA[i]++;
}
if(B[i] == 'C'){
prefBC[i]++;
}
if(B[i] == 'T'){
prefBT[i]++;
}
if(A[i] == 'A' && B[i] == 'C'){
prefAC[i]++;
}
if(A[i] == 'C' && B[i] == 'A'){
prefCA[i]++;
}
if(A[i] == 'A' && B[i] == 'T'){
prefAT[i]++;
}
if(A[i] == 'T' && B[i] == 'A'){
prefTA[i]++;
}
if(A[i] == 'C' && B[i] == 'T'){
prefCT[i]++;
}
if(A[i] == 'T' && B[i] == 'C'){
prefTC[i]++;
}
}
}
int get_distance(int x, int y){
if(prefDA[y] - (x == 0 ? 0 : prefDA[x - 1]) == prefBA[y] - (x == 0 ? 0 : prefBA[x - 1]) &&
prefDC[y] - (x == 0 ? 0 : prefDC[x - 1]) == prefBC[y] - (x == 0 ? 0 : prefBC[x - 1]) &&
prefDT[y] - (x == 0 ? 0 : prefDT[x - 1]) == prefBT[y] - (x == 0 ? 0 : prefBT[x - 1])){
int valAC = prefAC[y] - (x == 0 ? 0 : prefAC[x - 1]);
int valCA = prefCA[y] - (x == 0 ? 0 : prefCA[x - 1]);
int valAT = prefAT[y] - (x == 0 ? 0 : prefAT[x - 1]);
int valTA = prefTA[y] - (x == 0 ? 0 : prefTA[x - 1]);
int valCT = prefCT[y] - (x == 0 ? 0 : prefCT[x - 1]);
int valTC = prefTC[y] - (x == 0 ? 0 : prefTC[x - 1]);
int val1 = min(valAC, valCA);
int val2 = min(valAT, valTA);
int val3 = min(valTC, valCT);
valAC -= val1;
valCA -= val1;
valAT -= val2;
valTA -= val2;
valTC -= val3;
valCT -= val3;
int sum = valAC + valCA + valAT + valTA + valTC + valCT;
sum /= 3;
sum *= 2;
return sum + val1 + val2 + val3;
}
else{
return -1;
}
}
