/in/foo.c: In function 'main':
/in/foo.c:5:5: error: expected ',' or ';' before 'int'
     int b=20
     ^~~
/in/foo.c:9:1: error: expected declaration or statement at end of input
 }
 ^
/in/foo.c:4:9: warning: unused variable 'a' [-Wunused-variable]
     int a=10
         ^