```
#include <iostream>
#include <list>
#include <climits>
#include <cstdio>
using namespace std;
struct node {
int node_number;
int cost;
};
void create_graph ( int r , int c , list<struct node *> * list_ ) {
int a = r * 8 + c;
int n , m;
n = r + 2; m = c + 1;
if ( n >= 0 && n <= 7 && m >= 0 && m <= 7 ) {
struct node * nd = new struct node;
nd->node_number = n*8 + m;
nd->cost = r*n + c*m;
list_[a].push_back(nd);
}
n = r + 2; m = c - 1;
if ( n >= 0 && n <= 7 && m >= 0 && m <= 7 ) {
struct node * nd = new struct node;
nd->node_number = n*8 + m;
nd->cost = r*n + c*m;
list_[a].push_back(nd);
}
n = r - 2; m = c + 1;
if ( n >= 0 && n <= 7 && m >= 0 && m <= 7 ) {
struct node * nd = new struct node;
nd->node_number = n*8 + m;
nd->cost = r*n + c*m;
list_[a].push_back(nd);
}
n = r - 2; m = c - 1;
if ( n >= 0 && n <= 7 && m >= 0 && m <= 7 ) {
struct node * nd = new struct node;
nd->node_number = n*8 + m;
nd->cost = r*n + c*m;
list_[a].push_back(nd);
}
n = r + 1; m = c + 2;
if ( n >= 0 && n <= 7 && m >= 0 && m <= 7 ) {
struct node * nd = new struct node;
nd->node_number = n*8 + m;
nd->cost = r*n + c*m;
list_[a].push_back(nd);
}
n = r + 1; m = c - 2;
if ( n >= 0 && n <= 7 && m >= 0 && m <= 7 ) {
struct node * nd = new struct node;
nd->node_number = n*8 + m;
nd->cost = r*n + c*m;
list_[a].push_back(nd);
}
n = r - 1; m = c + 2;
if ( n >= 0 && n <= 7 && m >= 0 && m <= 7 ) {
struct node * nd = new struct node;
nd->node_number = n*8 + m;
nd->cost = r*n + c*m;
list_[a].push_back(nd);
}
n = r - 1; m = c - 2;
if ( n >= 0 && n <= 7 && m >= 0 && m <= 7 ) {
struct node * nd = new struct node;
nd->node_number = n*8 + m;
nd->cost = r*n + c*m;
list_[a].push_back(nd);
}
}
int dijkstra ( int s , int t , list<struct node *> *list_ ) {
int dist[64];
int visited[64];
for ( int i = 0 ; i < 64 ; i++ ) {
dist[i] = INT_MAX;
visited[i] = 0;
}
dist[s] = 0;
while ( s != -1 ) {
visited[s] = 1;
for ( list<struct node *>::iterator itr = list_[s].begin() ; itr != list_[s].end() ; itr++ ) {
struct node * v = (*itr);
if ( visited[v->node_number] == 1 )
continue;
if ( dist[v->node_number] > dist[s] + v->cost ) {
dist[v->node_number] = dist[s] + v->cost;
}
}
s = -1;
int min_distance = INT_MAX;
for ( int i = 0 ; i < 64 ; i++ ) {
if ( visited[i] == 0 && dist[i] < min_distance ) {
s = i;
min_distance = dist[i];
}
}
}
return dist[t];
}
int main ( int argc , char * argv[] ) {
list<struct node *> * list_ = new list<struct node *>[64];
for ( int i = 0 ; i < 8 ; i ++ ) {
for ( int j = 0 ; j < 8 ; j++ ) {
create_graph( i , j , list_ );
}
}
/*for ( int i = 0 ; i < 64 ; i++ ) {
cout << "Node " << i << " : ";
for ( list<struct node *>::iterator itr = list_[i].begin() ; itr != list_[i].end() ; itr++ ) {
cout << " " << (*itr)->node_number;
}
cout << endl;
}*/
int r1,c1,r2,c2;
while ( scanf("%d%d%d%d" , &r1 , &c1 , &r2 , &c2 ) != EOF ) {
cout << dijkstra ( r1 * 8 + c1 , r2 * 8 + c2 , list_ ) << endl;
}
return 0;
}
```

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