1 #include <iostream> 2 #include <cstring> 3 using namespace std; 4  5 const int size = 105; 6 int hash[size+5][size+5]; 7  8 int main() 9 {10     cin.sync_with_stdio(false);11     bool flag = false;12     int i , j , a , b , c , d , cnt;13     while( cin >> a >> c >> b >> d )14     {15         cnt = 0;16         memset( hash , false , sizeof(hash) );17         for( i = min(a,b)+1 ; i<=max(a,b) ; i++ )18             for( j = min(c,d)+1 ; j<=max(c,d) ; j++ )19                 hash[i][j] = true;20         while(1)21         {22             cin >> a >> c >> b >> d;23             if( a==-1 && b==-1 && c ==-1 && d==-1 )24                 break;25             else if( a==-2 && b==-2 && c==-2 && d==-2 )26             {27                 flag = true;28                 break;29             }    30             for( int i = min(a,b)+1 ; i<=max(a,b) ; i++ )31             {32                 for( int j = min(c,d)+1 ; j<=max(c,d) ; j++ )33                 {34                     if( !hash[i][j] )35                         hash[i][j] = true;36                 }37             }38         }39         for( int i = 0 ; i<=size ; i++ )40         {41             for( int j = 0 ; j<=size ; j++ )42             {43                 if( hash[i][j] )44                 {45                     cnt++;46                 }47             }48         }49         cout << cnt << endl;50         if( flag )51             break;52     }53     return 0;54 }