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: Wrong Answer)

/* ex5_4
   key_tree */

#include <stdio.h>
#include <string.h>

int main(void){
    int length, i, ans = 0, count = 0;
    // 文字数制限は10
    // 部分文字列の長さを見るarray
    char text[11], array[11];
    scanf("%s", &text);

    length = strlen(text);
    for(i = 0; i < length; i++){
        // ACGTであればcountを+1してarrayに記録
        if(text[i] == 'A'|| text[i] == 'C'|| text[i] == 'G'|| text[i] == 'T'){
            count++;
            array[i] = count;
        }
        // AGCTでなければcountを0に戻して記録
        else{
            count = 0;
            array[i] = count;   
        }
    }
    // 現時点でAGCT部分文字列の長さがarrayに記録されている
    for(i = 0; i < length - 1; i++){
        // arrayから最大の要素を取り出す
        if(ans < array[i]){
            ans = array[i];
        }
    }

    printf("%d\n", ans);

    return 0;
}