foo.c: In function 'main':
foo.c:4:11: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'b'
 {   int a b;
           ^
foo.c:4:11: error: 'b' undeclared (first use in this function)
foo.c:4:11: note: each undeclared identifier is reported only once for each function it appears in
foo.c:5:19: error: 'a' undeclared (first use in this function)
     scanf("%d,%d",a,b);
                   ^
foo.c:9:5: error: expected ';' before '}' token
     }
     ^