/in/foo.c: In function 'F':
/in/foo.c:3:1: error: expected declaration specifiers before 'if'
 if(n==1&&n==0)
 ^~
/in/foo.c:5:1: error: expected declaration specifiers before 'else'
 else return F(n-1)+F(n-2);
 ^~~~
/in/foo.c:7:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before '{' token
 {
 ^
/in/foo.c:11:1: error: expected '{' at end of input
 }
 ^
/in/foo.c:11:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^