#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 1e6 + 10, INF = 0x3f3f3f3f, MOD = 1E9 + 7;
string s, target = "123804765";
int d[][2] = {-1, 0, 0, -1, 1, 0, 0, 1};
int bfs() {
    map<string, int> mp;
    queue<string> q;
    q.push(s), mp[s] = 1;
    while (q.size()) {
        auto u = q.front(); q.pop();
        if (u == target) return mp[u] - 1;
        for (int i = 0; i < 4; i++) {
            int p = u.find('0');
            int x = p / 3 + d[i][0], y = p % 3 + d[i][1];
            if (x < 0 || x >= 3 || y < 0 || y >= 3) continue;
            string v(u);
            swap(v[p], v[x * 3 + y]);
            if (mp[v]) continue;
            q.push(v), mp[v] = mp[u] + 1;
        }
    }
    return -1;
}
int main(int argc, char* argv[]) {
    cin >> s, cout << bfs();
    return 0;
}