УРКОП 2011: F

#include <cstdio>
#include <iostream>

using namespace std;

int a[4][4], res = int(1e9);

bool eq(int x1, int y1, int x2, int y2) {
    x2--, y2--;
    return (a[x1][y1] == a[x1][y2] && a[x1][y1] == a[x2][y1] && a[x1][y1] == a[x2][y2]);
}

bool check() {
    return (eq(0, 0, 2, 2) && eq(0, 2, 2, 4) && eq(2, 0, 4, 2) && eq(2, 2, 4, 4));
}

void dfs(int h) {
    if (h > 10) return;

    if (check()) {
        res = min(res, h);
        return;
    }
    if (h > res) return;

    int cpy[4][4];

    for (int i = 0; i < 4; i++)
        for (int j = 0; j < 4; j++)
            cpy[i][j] = a[i][j];

    a[3][1] = cpy[1][0];
    a[2][3] = cpy[3][1];
    a[0][2] = cpy[2][3];
    a[1][0] = cpy[0][2];

    dfs(h + 1);

    a[1][0] = cpy[3][1];
    a[3][1] = cpy[2][3];
    a[2][3] = cpy[0][2];
    a[0][2] = cpy[1][0];

    dfs(h + 1);

    for (int i = 0; i < 4; i++)
        for (int j = 0; j < 4; j++)
            a[i][j] = cpy[i][j];

    a[2][0] = cpy[0][1];
    a[3][2] = cpy[2][0];
    a[1][3] = cpy[3][2];
    a[0][1] = cpy[1][3];

    dfs(h + 1);

    a[0][1] = cpy[2][0];
    a[2][0] = cpy[3][2];
    a[3][2] = cpy[1][3];
    a[1][3] = cpy[0][1];

    dfs(h + 1);

    for (int i = 0; i < 4; i++)
        for (int j = 0; j < 4; j++)
            a[i][j] = cpy[i][j];

    a[3][0] = cpy[0][0];
    a[3][3] = cpy[3][0];
    a[0][3] = cpy[3][3];
    a[0][0] = cpy[0][3];

    dfs(h + 1);

    a[0][0] = cpy[3][0];
    a[3][0] = cpy[3][3];
    a[3][3] = cpy[0][3];
    a[0][3] = cpy[0][0];

    dfs(h + 1);

    for (int i = 0; i < 4; i++)
        for (int j = 0; j < 4; j++)
            a[i][j] = cpy[i][j];

    a[1][2] = cpy[1][1];
    a[2][2] = cpy[1][2];
    a[2][1] = cpy[2][2];
    a[1][1] = cpy[2][1];

    dfs(h + 1);

    a[1][1] = cpy[1][2];
    a[1][2] = cpy[2][2];
    a[2][2] = cpy[2][1];
    a[2][1] = cpy[1][1];

    dfs(h + 1);

    for (int i = 0; i < 4; i++)
        for (int j = 0; j < 4; j++)
            a[i][j] = cpy[i][j];
}

int main() {
    for (int i = 0; i < 4; i++)
        for (int j = 0; j < 4; j++)
            cin >> a[i][j];

    dfs(0);

    cout << res;

    return 0;
}