import java.util.Scanner;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
// 注意 hasNext 和 hasNextLine 的区别
while (in.hasNext()) { // 注意 while 处理多个 case
String s = in.nextLine();
String cur = "";
String res = "";
int len = s.length();
int i = 0;
for( i = 0; i < len; i++) {
char ch = s.charAt(i);
if(ch >= '0' && ch <= '9') {
cur += ch + "";
} else {
if(cur.length() > res.length()) {
res = cur;
} else {
cur = "";
}
}
}
if(i == len && cur.length() > res.length()) {
res = cur;
}
System.out.print(res);
}
}
}