/in/foo.c:1:1: warning: return type defaults to 'int' [-Wimplicit-int]
 input()
 ^~~~~
/in/foo.c: In function 'input':
/in/foo.c:1:1: error: expected '{' at end of input
/in/foo.c:1:1: warning: control reaches end of non-void function [-Wreturn-type]
 input()
 ^~~~~