**A. Possible Subscribers**↵
↵
**Input file:** standard input↵
↵
**Output file:** standard output↵
↵
**Time limit:** 1 second↵
↵
**Memory limit:** 256 megabytes↵
↵
MegaMath Channel starts at 0 subscribers. Every day i, the channel gains xi subscribers. Help MegaMath↵
determine whether this is a possible sequence of values of xi (the total number of subscribers must stay↵
≥ 0.)↵
↵
**Input**↵
↵
The first line contains the number of days n (1 <= n <= 100).↵
The next n lines contain a single integer xi.↵
↵
**Output**↵
↵
Print "Yes" if the total number of subscribers MegaMath Channel has is, at any given day, >= 0. Otherwise,↵
print "No".
↵
**Input file:** standard input↵
↵
**Output file:** standard output↵
↵
**Time limit:** 1 second↵
↵
**Memory limit:** 256 megabytes↵
↵
MegaMath Channel starts at 0 subscribers. Every day i, the channel gains xi subscribers. Help MegaMath↵
determine whether this is a possible sequence of values of xi (the total number of subscribers must stay↵
≥ 0.)↵
↵
**Input**↵
↵
The first line contains the number of days n (1 <= n <= 100).↵
The next n lines contain a single integer xi.↵
↵
**Output**↵
↵
Print "Yes" if the total number of subscribers MegaMath Channel has is, at any given day, >= 0. Otherwise,↵
print "No".