// input checker

#include <cassert>
#include <iostream>
using namespace std;
int main(){
  string s;
  cin >> s;
  for(auto c : s){
    assert( ('a'<=c && c<='z') || ('A'<=c && c<='Z') || ('0'<=c && c<='9') );
  }
  assert( 1 <= s.size() && s.size() <= 100);

  cerr << "ok" << endl;
  return 0;
}