const fi='hcn.inp'     

fo='hcn.out'

var f1,f2:text;   

a,b:array[1..100]of integer;   

i,j,n:integer;

begin

assign(f1,fi); reset(f1);

assign(f2,fo); rewrite(f2);

n:=0;

while not eof(f1) do 

begin     

inc(n);     

readln(f1,a[n],b[n]); 

end;

for i:=1 to n do 

writeln(f2,2*(a[i]+b[i]),' ',a[i]*b[i]);

close(f1);

close(f2);

end.

const fi='bt1.inp'

fo='bt1.out'

var f1,f2:text;

a,b:integer;

begin

assign(f1,fi); reset(f1);

assign(f2,fo); rewrite(f2);

readln(f1,a,b);

writeln(f2,'Chu vi la: ',(a+b)*2);

writeln(f2,'Dien tich la: ',a*b);

close(f1);

close(f2);

end.

#include <bits/stdc++.h>

using namespace std;

long long a,b;

int main()

{

freopen("sn.inp","r",stdin);

freopen("cn.out","w",stdout);

cin>>a>>b;

cout<<a*b;

return 0;

}

#include <bits/stdc++.h>
using namespace std;
unsigned long long a[1000],i,n,uc;
//chuongtrinhcon
unsigned long long ucln(long long a,long long b)
{
    if (b==0) return(a);
    else return(ucln(b,a%b));
}
//chuongtrinhchinh
int main()
{
    freopen("sn3.inp","r",stdin);
    freopen("uc.out","w",stdout);
    cin>>n;

for (i=1; i<=n; i++) cin>>a[i];

uc=ucln(a[1],a[2]);

for (i=3; i<=n; i++)

uc=ucln(uc,a[i]);

cout<<uc;
    return 0;
}

uses crt;

const fi='x.inp'

var f1:text;

a,b:array[1..100]of integer;

i,n:integer;

begin

assign(f1,fi); reset(f1);

n:=0;

while not eof(f1) do 

begin

n:=n+1;

readln(f1,a[n],b[n]);

end;

for i:=1 to n do 

  begin

writeln('Chu vi dong ',i,' la: ',(a[i]+b[i])*2);

writeln('Dien tich dong ',i,' la: ',a[i]*b[i]);

end;

close(f1);

readln;

end.

#include <bits/stdc++.h>
using namespace std;
long long a,b;
//chuongtrinhcon
long long gcd(long long a,long long b)
{
    if (b==0) return(a);
    return gcd(b,a%b);
}
//chuongtrinhchinh
int main()
{

freopen("songuyen.inp","r",stdin);
cin>>a>>b;
cout<<gcd(a,b);
return 0;
}

uses crt;

const fi='so.inp'

var f1:text;

a,b:integer;

begin

clrscr;

assign(f1,fi); reset(f1);

while not eof(f1) do 

 begin

readln(f1,a,b);

writeln((a+b)/2:4:2);

end;

close(f1);

readln;

end.

const fi='dulieu.txt'     

fo='ketqua.txt'

var f1,f2:text;   

a,b,c,d:array[1..100]of integer;   

i,n,dem,dem1:integer;

begin

assign(f1,fi); reset(f1);

assign(f2,fo); rewrite(f2);

n:=0;

while not eof(f1) do 

begin     

n:=n+1;     

readln(f1,a[n],b[n]); 

end;

dem:=0;

dem1:=0;

for i:=1 to n do 

if a[i]>b[i] then     

begin       

inc(dem);       

inc(dem1);       

c[dem]:=a[i];       

d[dem]:=b[i];     

end 

else begin         

inc(dem);         

inc(dem1);         

c[dem]:=b[i];         

d[dem]:=a[i];       

end;

for i:=1 to dem do 

write(f2,c[i]:4);

writeln(f2);

for i:=1 to dem1 do 

write(f2,d[i]:4);

close(f1);

close(f2);

end.