foo.c: In function ‘main’:
foo.c:5:9: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘if’
    5 |         if("x是素数"）
      |         ^~
foo.c:5:21: error: expected ‘)’ before ‘）’
    5 |         if("x是素数"）
      |           ~         ^~
      |                     )
foo.c:10:1: error: expected expression before ‘}’ token
   10 | }
      | ^
foo.c: At top level:
foo.c:11:5: error: expected identifier or ‘(’ before ‘return’
   11 |     return 0
      |     ^~~~~~