/in/foo.c:1:1: warning: return type defaults to 'int' [-Wimplicit-int]
 main(){for(registr int i=70000000;i--;)printf("70000000");}
 ^~~~
/in/foo.c: In function 'main':
/in/foo.c:1:12: error: 'registr' undeclared (first use in this function)
 main(){for(registr int i=70000000;i--;)printf("70000000");}
            ^~~~~~~
/in/foo.c:1:12: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:1:20: error: expected ';' before 'int'
 main(){for(registr int i=70000000;i--;)printf("70000000");}
                    ^~~
/in/foo.c:1:35: error: 'i' undeclared (first use in this function)
 main(){for(registr int i=70000000;i--;)printf("70000000");}
                                   ^
/in/foo.c:1:40: warning: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
 main(){for(registr int i=70000000;i--;)printf("70000000");}
                                        ^~~~~~
/in/foo.c:1:40: warning: incompatible implicit declaration of built-in function 'printf'
/in/foo.c:1:40: note: include '<stdio.h>' or provide a declaration of 'printf'