Mã nộp #14450 | Cặp số tương đồng

Main.cc: In function ‘int main()’:
Main.cc:29:16: error: ‘__gcd’ was not declared in this scope
             if(__gcd(i,j) == 1)
                ^~~~~
Main.cc:29:16: note: suggested alternative: ‘__gid_t’
             if(__gcd(i,j) == 1)
                ^~~~~
                __gid_t