View Compilation Error

0_0_39561441_23847.cpp: In function 'int main()':
0_0_39561441_23847.cpp:19:18: error: unable to find numeric literal operator 'operator""x'
   19 |            int k=2x*y/__gcd(2x,y);//最小公倍数
      |                  ^~
0_0_39561441_23847.cpp:19:18: note: use '-fext-numeric-literals' to enable more built-in suffixes
0_0_39561441_23847.cpp:19:29: error: unable to find numeric literal operator 'operator""x'
   19 |            int k=2x*y/__gcd(2x,y);//最小公倍数
      |                             ^~
0_0_39561441_23847.cpp:19:29: note: use '-fext-numeric-literals' to enable more built-in suffixes