朴素解法…

public class Main{
	public static void main(String[] args){		Scanner sc = new Scanner(System.in);
		while(sc.hasNext()){
			int a = sc.nextInt();
			String str = Integer.toBinaryString(a);
			int count=0;
			int max = 0;
			for(int i=0;i<str.length();i++){
				char ch = str.charAt(i);
				if(ch=='1'){
					count++;
					if((i==str.length()-1)||(i!=str.length()-1 && str.charAt(i+1)=='0')){
						if(count>max){
							max=count;
						}
					}
				}
				else{
					count=0;
				}
			}
			System.out.println(max);
		}
	}
}