oracle failed on case 3: runtime error: exit status 2
panic: runtime error: index out of range [-1]

goroutine 1 [running]:
main.main()
	/home/ubuntu/codeforces/1000-1999/1800-1899/1850-1859/1858/1858E1.go:52 +0x928

input:
26
+ 482141
- 1
+ 696930
+ 763022
- 2
+ 892239
- 1
+ 487607
!
+ 871229
!
- 2
+ 172054
?
?
+ 933953
?
- 1
+ 447055
+ 998951
+ 862938
- 1
!
- 2
+ 400674
?
exit status 1