import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        
        Scanner scanner = new Scanner(System.in);
        long N = scanner.nextLong();
        int n = (int)Math.sqrt(N);
        int X = 0;
        
        for(int i=1; i<=n; i++){
            if(N%i==0){
                X = i;
            }
        }
        
        N /= X;
        
        int valLenN = String.valueOf(N).length();
        int valLenX = String.valueOf(X).length();
        
        if(valLenX<=valLenN){
            System.out.println(valLenN);
        }else{
            System.out.println(valLenX);
        }
        
        
    }
}

/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz