Problem:
Score : 200 points

Problem Statement

You are given a string S consisting of uppercase English letters. Find the length of the longest ACGT string that is a substring (see Notes) of S.

Here, a ACGT string is a string that contains no characters other than A, C, G and T.

Notes

A substring of a string T is a string obtained by removing zero or more characters from the beginning and the end of T.

For example, the substrings of ATCODER include TCO, AT, CODER, ATCODER and (the empty string), but not AC.

Constraints

S is a string of length between 1 and 10 (inclusive).

Each character in S is an uppercase English letter.

Input

Input is given from Standard Input in the following format:

S

Output

Print the length of the longest ACGT string that is a substring of S.

Sample Input 1

ATCODER

Sample Output 1

3

Among the ACGT strings that are substrings of ATCODER, the longest one is ATC.

Sample Input 2

HATAGAYA

Sample Output 2

5

Among the ACGT strings that are substrings of HATAGAYA, the longest one is ATAGA.

Sample Input 3

SHINJUKU

Sample Output 3

0

Among the ACGT strings that are substrings of SHINJUKU, the longest one is (the empty string).

Solution in C (GCC 9.2.1) (judge verdict: Accepted)

/* ex2-4
    kas056*/

#include<stdio.h>
#define SIZE 15


int main(void){
    char sentence[SIZE];
    char *p;
    int length = 0;
    int maxlen = 0;

    scanf("%s", sentence);

    p = sentence;//ポインタを連結

    //ヌル文字に到達するまで操作を行う
    while(*p){
        //該当する文字があったらカウント開始。
        if(*p == 'A' || *p == 'C' || *p == 'G' || *p == 'T'){
            length++;
        }
        else{//該当するものが続かなければ、カウントをリセットする。
            length = 0;
        }

        if(length > maxlen){
            maxlen = length;//最高記録を超えたら更新
        }

        p++;//次の文字に進む
    }

    printf("%d", maxlen);

    return 0;

}