#include <iostream>
#include <string>
#include <cassert>
using namespace std;
const int MAX = 4;
struct Matrix
{
int a[MAX][MAX];
Matrix()
{
for (int i=0;i<MAX;i++)
for (int j=0;j<MAX;j++)
a[i][j] = 0;
}
void add(const Matrix &o)
{
for (int i=0;i<MAX;i++)
for (int j=0;j<MAX;j++)
a[i][j] += o.a[i][j];
}
void sub(const Matrix &o)
{
for (int i=0;i<MAX;i++)
for (int j=0;j<MAX;j++)
a[i][j] -= o.a[i][j];
}
int swapdistance() const
{
int mtot = 0;
int si[MAX];
for (int i=0;i<MAX;i++)
si[i] = 0;
for (int i=0;i<MAX;i++)
for (int j=0;j<MAX;j++)
{
mtot += a[i][j];
si[i] += a[i][j];
si[j] -= a[i][j];
}
for (int node=0;node<MAX;node++)
if (si[node])
return -1;
Matrix aux = *this;
int cycles = 0;
for (int i=0;i<MAX;i++)
{
cycles += aux.a[i][i];
aux.a[i][i] = 0;
}
for (int i=0;i<MAX;i++)
for (int j=0;j<i;j++)
{
int c = min(aux.a[i][j], aux.a[j][i]);
cycles += c;
aux.a[i][j] -= c;
aux.a[j][i] -= c;
}
for (int i=0;i<MAX;i++)
for (int j=0;j<i;j++)
for (int k=0;k<j;k++)
{
int c;
c = min(aux.a[i][j], min(aux.a[j][k], aux.a[k][i])); cycles += c; aux.a[i][j] -= c; aux.a[j][k] -= c; aux.a[k][i] -= c;;
c = min(aux.a[i][k], min(aux.a[k][j], aux.a[j][i])); cycles += c; aux.a[i][k] -= c; aux.a[k][j] -= c; aux.a[j][i] -= c;;
}
int remainingEdges = 0;
for (int i=0;i<MAX;i++)
for (int j=0;j<MAX;j++)
remainingEdges += aux.a[i][j];
assert(remainingEdges % MAX == 0);
cycles += remainingEdges / MAX;
return mtot - cycles;
}
};
int charValues[256];
string globalA, globalB;
void init(string a, string b)
{
globalA = a;
globalB = b;
charValues['A'] = 0;
charValues['T'] = 1;
charValues['C'] = 2;
charValues['G'] = 3;
}
int get_distance(int i,int j)
{
Matrix mat;
for (int k = i; k <= j; k++) {
int x = charValues[int(globalA[k])];
int y = charValues[int(globalB[k])];
mat.a[x][y] += 1;
}
if (mat.a[0][1] != mat.a[1][0]) {
return -1;
} else {
return mat.a[0][1];
}
}
