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)

/* ex 5_4
   ruuu0048 */

#include <stdio.h>


int main(void){
    //10文字以下なので最大の要素数は\0を含めて11
    char word[11],*ptr;
    //count:数える変数 count_max:最大のACGT文字列の長さ
    int count=0,count_max=0;

    scanf("%s", &word[0]); //文字列を入力

    ptr = &word[0]; //文字列の先頭のアドレスを代入

    while(*ptr){ //文字列の最後まで繰り返す
        if(*ptr=='A' ||*ptr=='C'||*ptr=='G'||*ptr=='T'){ //もしももACGTのどれかだったら
            count++; //数える
            if(count > count_max){ //数えたものが今までの最大よりも大きかったら
                count_max = count; //最大値を更新
            }
        }
        else{ //ACGT以外だったら
            count=0; //カウンターをリセット
        }
        ptr++; //ptrの位置を一つ右にずらす
    }
    printf("%d\n",count_max); //最大のAGCT文字列の長さを出力

    return 0;
}