foo.c:2:1: warning: return type defaults to 'int' [-Wreturn-type]
foo.c: In function 'main':
foo.c:4:1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'scanf'
foo.c:5:10: error: 'b' undeclared (first use in this function)
foo.c:5:10: note: each undeclared identifier is reported only once for each function it appears in
foo.c:7:1: error: expected ';' before '}' token
foo.c:7:1: warning: control reaches end of non-void function [-Wreturn-type]