4864: Messenger
内存限制：256 MB
时间限制：2 S
题面：传统
评测方式：文本比较
上传者：
提交：1
通过：1
题目描述
D. Messenger
time limit per test
2 seconds
memory limit per test
512 megabytes
input
standard input
output
standard output
Each employee of the "Blake Techologies" company uses a special messaging app "Blake Messenger". All the stuff likes this app and uses it constantly. However, some important futures are missing. For example, many users want to be able to search through the message history. It was already announced that the new feature will appear in the nearest update, when developers faced some troubles that only you may help them to solve.
All the messages are represented as a strings consisting of only lowercase English letters. In order to reduce the network load strings are represented in the special compressed form. Compression algorithm works as follows: string is represented as a concatenation of n blocks, each block containing only equal characters. One block may be described as a pair (li,ci), where li is the length of the i-th block and ci is the corresponding letter. Thus, the string s may be written as the sequence of pairs
.
Your task is to write the program, that given two compressed string t and s finds all occurrences of s in t. Developers know that there may be many such occurrences, so they only ask you to find the number of them. Note that p is the starting position of some occurrence of s in t if and only if tptp+1...tp+|s|-1=s, where ti is the i-th character of string t.
Note that the way to represent the string in compressed form may not be unique. For example string "aaaa" may be given as
, 
, 
...
All the messages are represented as a strings consisting of only lowercase English letters. In order to reduce the network load strings are represented in the special compressed form. Compression algorithm works as follows: string is represented as a concatenation of n blocks, each block containing only equal characters. One block may be described as a pair (li,ci), where li is the length of the i-th block and ci is the corresponding letter. Thus, the string s may be written as the sequence of pairs
. Your task is to write the program, that given two compressed string t and s finds all occurrences of s in t. Developers know that there may be many such occurrences, so they only ask you to find the number of them. Note that p is the starting position of some occurrence of s in t if and only if tptp+1...tp+|s|-1=s, where ti is the i-th character of string t.
Note that the way to represent the string in compressed form may not be unique. For example string "aaaa" may be given as
, , ...
Input
The first line of the input contains two integers n and m (1≤n,m≤200000)− the number of blocks in the strings t and s, respectively. The second line contains the desc
The second line contains the desc
Output
Print a single integer− the number of occurrences of s in t.
Examples
Input
5 3 3-a 2-b 4-c 3-a 2-c 2-a 2-b 1-c
Output
1
Input
6 1 3-a 6-b 7-a 4-c 8-e 2-a 3-a
Output
6
Input
5 5 1-h 1-e 1-l 1-l 1-o 1-w 1-o 1-r 1-l 1-d
Output
0
Note
In the first sample, t = "aaabbccccaaacc", and string s = "aabbc". The only occurrence of string s in string t starts at position p=2. In the second sample, t = "aaabbbbbbaaaaaaacccceeeeeeeeaa", and s = "aaa". The occurrences of s in t start at positions p=1, p=10, p=11, p=12, p=13 and p=14.
输入样例 复制
输出样例 复制