foo.c:1:9: error: expected '=', ',', ';', 'asm' or '__attribute__' before '<' token
 include <stdio.h>
         ^
foo.c: In function 'main':
foo.c:7:1: warning: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
 scanf("%s" , a);
 ^
foo.c:7:1: warning: incompatible implicit declaration of built-in function 'scanf' [enabled by default]
foo.c:7:14: error: 'a' undeclared (first use in this function)
 scanf("%s" , a);
              ^
foo.c:7:14: note: each undeclared identifier is reported only once for each function it appears in
foo.c:21:5: warning: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
     printf("Right\n");
     ^
foo.c:21:5: warning: incompatible implicit declaration of built-in function 'printf' [enabled by default]
foo.c:26:5: warning: incompatible implicit declaration of built-in function 'printf' [enabled by default]
     printf("%s\n" , a);
     ^