#include<iostream>
#include<vector>
#include<sstream>
using namespace std;
int main(){
    string s;
    getline(cin ,s);
    
    for (char ch:s){
        
        if(!(isalpha(c)|| c==' ')){
            cout<<"Invalid input";
            return 0;
        }
    }
    vector <string> words;
    string word;
    stringstream ss(s);
    while(ss>>word){
        words.push_back(word);
    }
    int maxlen =0;
    for(string w : words)
    }
    return 0;
}