View Compilation Error

0_0_39558991_1949.cpp: In function 'int main()':
0_0_39558991_1949.cpp:19:23: error: unable to find numeric literal operator 'operator""x'
   19 |                 int k=2x*y/__gcd(2x,y);//最小公倍数
      |                       ^~
0_0_39558991_1949.cpp:19:23: note: use '-fext-numeric-literals' to enable more built-in suffixes
0_0_39558991_1949.cpp:19:34: error: unable to find numeric literal operator 'operator""x'
   19 |                 int k=2x*y/__gcd(2x,y);//最小公倍数
      |                                  ^~
0_0_39558991_1949.cpp:19:34: note: use '-fext-numeric-literals' to enable more built-in suffixes