foo.c: In function 'main':
foo.c:40:11: error: expected identifier or '(' before ',' token
foo.c:42:15: error: 'bijiao2' undeclared (first use in this function)
foo.c:42:15: note: each undeclared identifier is reported only once for each function it appears in
foo.c:42:23: error: 'bijiao3' undeclared (first use in this function)
foo.c:50:6: error: 'k' undeclared (first use in this function)
foo.c:59:6: error: 'sum' undeclared (first use in this function)
foo.c:41:7: warning: unused variable 'now' [-Wunused-variable]