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)

/* ex5_4
    fmuacshai */
#include <stdio.h>

#define SIZE 80

int main(void){
    //配列の定義
    char string[SIZE];
    //ポインタの定義
    char *ptr;
    //配列の定義と初期化
    int number[SIZE]={0};
    //ポインタの定義
    int *sequence;
    //答えanswerと文字数カウントcount、for文で使うiを定義
    int answer=0,count=0,i;
    //文字列の入力
    scanf("%s",string);
    //ポインタと配列を対応
    ptr=&string[0];
    sequence=&number[1];
    //NULLが出るまで
    while(*ptr){
        //A,T,G,Cだったら
        if(*ptr=='A'||*ptr=='T'||*ptr=='G'||*ptr=='C'){
            *sequence=*(sequence-1)+1;
        //それ以外
        }else{
            *sequence=0;
        }
        ptr++;
        sequence++;
        count++;
    }
    //sequenceの位置を戻す
    sequence=sequence-count;
    //文字数分チェック
    for(i=0;i<count;i++){
        //sequence内で最大のものをanswerに
        if(*sequence>answer){
            answer=*sequence;
        }
        sequence++;
    }
    //出力
    printf("%d\n",answer);
    return 0;
}