************************* 2419 ***************************
#include <iostream>
using namespace std;
long long a,b,s,dif,s1,s2, mij;
int main()
{
cin >> a >> b;
if (a>b) dif=a-b;
else dif=b-a;
mij=dif/2;
if (mij%2==0) s1=(mij/2)*(1+mij);
else s1=mij*((1+mij)/2);
if (dif%2==0)
{
s=2*s1;
}
else
{
if ((mij+1)%2==0) s2=((mij+1)/2)*(2+mij);
else s2=((2+mij)/2)*(mij+1);
s=s1+s2;
}
cout << s;
}
*****************************2911 ************************
#include <iostream>
using namespace std;
long long n, t, z=1, cif, nrcif=1, i;
int main()
{
cin >> n;
t=n;
while (t>9)
{
++nrcif;
z=z*10;
t=t/10;
}
t=n;
for (i=1; i<=nrcif; ++i)
{
cif=t/z; t=t%z; z=z/10;
switch (cif)
{
case 0:
{cout << "@@@@@"<<endl; cout <<"@ @"<<endl; cout <<"@ @"<<endl;
cout <<"@ @"<<endl; cout << "@@@@@"<<endl;
break;}
case 1:
{cout << " @ "<<endl; cout <<" @@ "<<endl; cout <<" @ "<<endl;
cout <<" @ "<<endl; cout << "@@@@@"<<endl;
break;}
case 2:
{cout << "@@@@ "<<endl; cout <<"@ @ "<<endl; cout <<" @ "<<endl;
cout <<" @ "<<endl; cout << "@@@@ "<<endl;
break;}
case 3:
{cout << "@@@@@"<<endl; cout <<" @"<<endl; cout <<"@@@@@"<<endl;
cout <<" @"<<endl; cout << "@@@@@"<<endl;
break;}
case 4:
{cout << "@ @"<<endl; cout <<"@ @"<<endl; cout <<"@@@@@"<<endl;
cout <<" @"<<endl; cout << " @"<<endl;
break;}
case 5:
{cout << "@@@@@"<<endl; cout <<"@ "<<endl; cout <<"@@@@@"<<endl;
cout <<" @"<<endl; cout << "@@@@@"<<endl;
break;}
case 6:
{cout << "@@@@@"<<endl; cout <<"@ "<<endl; cout <<"@@@@@"<<endl;
cout <<"@ @"<<endl; cout << "@@@@@"<<endl;
break;}
case 7:
{cout << "@@@@ "<<endl; cout <<" @ "<<endl; cout <<" @@@"<<endl;
cout <<" @ "<<endl; cout << " @ "<<endl;
break;}
case 8:
{cout << "@@@@@"<<endl; cout <<"@ @"<<endl; cout <<"@@@@@"<<endl;
cout <<"@ @"<<endl; cout << "@@@@@"<<endl;
break;}
case 9:
{cout << "@@@@@"<<endl; cout <<"@ @"<<endl; cout <<"@@@@@"<<endl;
cout <<" @"<<endl; cout << " @"<<endl;
break;}
}
cout << endl;
}
}