#include <bits/stdc++.h>
#define fi first
#define se second
#define vi_a vector<int>a;
#define p_b push_back
#define ll long long
#define pll pair<ll,ll>
#define pii pair<int,int>
#define m_p make_pair
#define fast_io cin.tie(0);cout.tie(0);ios_base::sync_with_stdio(0);
#define getfiles ifstream cin("cheval.in");ofstream cout("cheval.out");
#define closefiles cin.close();cout.close();
#define all(x) x.begin(),x.end()
#define sset ordered_set
#define sqr(x) (x)*(x)
#define pw(x) (1ll << x)
#define sz(x) (int)x.size()
#define endl "\n"
bool cmp(ll a,ll b){
    return a>b;
}
using namespace std;

int main()
{
    getfiles;
    fast_io;
    queue<pair<ll,ll> >positions;
    pair<ll,ll> vvod;
    int a[8][8];
    for(int i=0;i<8;i++){
        for(int j=0;j<8;j++){
            a[i][j]=-1;
        }
    }
    int dd[8][8];
    for(int i=0;i<8;i++){
        for(int j=0;j<8;j++){
            dd[i][j]=-1;
        }
    }
    char g;
    cin>>g>>vvod.second;
    vvod.second--;
    vvod.first=g-'a';
    a[vvod.first][vvod.second]=0;
    dd[vvod.first][vvod.second]=0;
    positions.push(vvod);
    ll x1,y1;
    cin>>g>>y1;
    y1--;
    x1=g-'a';
    while(positions.size()!=0){
        ll x=positions.front().first,y=positions.front().second;
        ll count_1=dd[x][y]/2+dd[x][y]%2,count_2=dd[x][y]/2;
        if(count_1==count_2){
            count_1++;
        }
        else{
            count_2++;
        }
       if(positions.front().first+count_1<8 && positions.front().second+count_2<8){
            positions.push({positions.front().first+count_1,positions.front().second+count_2});
            if(a[positions.front().first+count_1][positions.front().second+count_2]==-1)
            a[positions.front().first+count_1][positions.front().second+count_2]=count_1+count_2;
            dd[positions.front().first+count_1][positions.front().second+count_2]=count_1+count_2;
        }
        if(positions.front().first-count_1>=0 && positions.front().second+count_2<8){
            positions.push({positions.front().first-count_1,positions.front().second+count_2});
            if(a[positions.front().first-count_1][positions.front().second+count_2]==-1)
            a[positions.front().first-count_1][positions.front().second+count_2]=count_1+count_2;
            dd[positions.front().first-count_1][positions.front().second+count_2]=count_1+count_2;
        }
        if(positions.front().first+count_1<8 && positions.front().second-count_2>=0  ){
            positions.push({positions.front().first+count_1,positions.front().second-count_2});
            if(a[positions.front().first+count_1][positions.front().second-count_2]==-1)
            a[positions.front().first+count_1][positions.front().second-count_2]=count_1+count_2;
            dd[positions.front().first+count_1][positions.front().second-count_2]=count_1+count_2;
        }
        if(positions.front().first-count_1>=0 && positions.front().second-count_2>=0 ){
            positions.push({positions.front().first-count_1,positions.front().second-count_2});
            if(a[positions.front().first-count_1][positions.front().second-count_2]==-1)a[positions.front().first-count_1][positions.front().second-count_2]=count_1+count_2;
            dd[positions.front().first-count_1][positions.front().second-count_2]=count_1+count_2;
        }
         if(positions.front().first+count_2<8 && positions.front().second+count_1<8 ){
            positions.push({positions.front().first+count_2,positions.front().second+count_1});
            if(a[positions.front().first+count_2][positions.front().second+count_1]==-1)a[positions.front().first+count_2][positions.front().second+count_1]=count_1+count_2;
            dd[positions.front().first+count_2][positions.front().second+count_1]=count_1+count_2;
        }
        if(positions.front().first-count_2>=0 && positions.front().second+count_1<8 ){
            positions.push({positions.front().first-count_2,positions.front().second+count_1});
            if(a[positions.front().first-count_2][positions.front().second+count_1]==-1)
             a[positions.front().first-count_2][positions.front().second+count_1]=count_1+count_2;
              dd[positions.front().first-count_2][positions.front().second+count_1]=count_1+count_2;
        }
        if(positions.front().first+count_2<8 && positions.front().second-count_1>=0){
            positions.push({positions.front().first+count_2,positions.front().second-count_1});
            if( a[positions.front().first+count_2][positions.front().second-count_1]==-1)a[positions.front().first+count_2][positions.front().second-count_1]=count_1+count_2;
            dd[positions.front().first+count_2][positions.front().second-count_1]=count_1+count_2;
        }
        if(positions.front().first-count_2>=0 && positions.front().second-count_1>=0 ){
            positions.push({positions.front().first-count_2,positions.front().second-count_1});
            if(a[positions.front().first-count_2][positions.front().second-count_1]==-1)  {
                 a[positions.front().first-count_2][positions.front().second-count_1]=count_1+count_2;
            }
            dd[positions.front().first-count_2][positions.front().second-count_1]=count_1+count_2;
        }
        positions.pop();
    }
    cout<<a[x1][y1];
    closefiles;
    return 0;
}