A

 1 #include <iostream>
 2 
 3 using namespace std;
 4 
 5 int main()
 6 {
 7     int a, b;
 8     while(cin>>a>>b)
 9     {
10         cout<<a+b<<endl;
11     }
12     return 0;
13 }

B

 1 #include <iostream>
 2 
 3 using namespace std;
 4 
 5 int main()
 6 {
 7     int T, a, b;
 8     cin>>T;
 9     while(T--)
10     {
11         cin>>a>>b;
12         cout<<a+b<<endl;
13     }
14     return 0;
15 }

C

 1 #include <iostream>
 2 
 3 using namespace std;
 4 
 5 int main()
 6 {
 7     int a, b;
 8     while(cin>>a>>b)
 9     {
10         if(a==0&&b==0)continue;
11         cout<<a+b<<endl;
12     }
13     return 0;
14 }

D

 1 #include <iostream>
 2 
 3 using namespace std;
 4 
 5 int main()
 6 {
 7     int n, x, sum;
 8     while(cin>>n&&n)
 9     {
10         sum = 0;
11         for(int i = 0; i < n; i++)
12         {
13             cin>>x;
14            sum+=x;
15         }
16 
17         cout<<sum<<endl;
18     }
19     return 0;
20 }

E

 1 #include <iostream>
 2 
 3 using namespace std;
 4 
 5 int main()
 6 {
 7     int n, x, sum, T;
 8     cin>>T;
 9     while(T--)
10     {
11         sum = 0;
12         cin>>n;
13         for(int i = 0; i < n; i++)
14         {
15             cin>>x;
16            sum+=x;
17         }
18 
19         cout<<sum<<endl;
20     }
21     return 0;
22 }

F

 1 #include <iostream>
 2 
 3 using namespace std;
 4 
 5 int main()
 6 {
 7     int n, x, sum;
 8     while(cin>>n)
 9     {
10         sum = 0;
11         for(int i = 0; i < n; i++)
12         {
13             cin>>x;
14            sum+=x;
15         }
16 
17         cout<<sum<<endl;
18     }
19     return 0;
20 }

G

 1 #include <iostream>
 2 
 3 using namespace std;
 4 
 5 int main()
 6 {
 7     int a, b;
 8     while(cin>>a>>b)
 9     {
10         cout<<a+b<<endl<<endl;
11     }
12     return 0;
13 }

H

 1 #include <iostream>
 2 
 3 using namespace std;
 4 
 5 int main()
 6 {
 7     int n, x, sum, T;
 8     cin>>T;
 9     sum = 0;
10     cin>>n;
11     for(int i = 0; i < n; i++)
12     {
13         cin>>x;
14         sum+=x;
15     }
16     cout<<sum<<endl;
17     T--;
18     while(T--)
19     {
20         sum = 0;
21         cin>>n;
22         for(int i = 0; i < n; i++)
23         {
24             cin>>x;
25             sum+=x;
26         }
27 
28         cout<<endl<<sum<<endl;
29     }
30     return 0;
31 }