Find The Biggest String(word) In Sentence(with noise)

#include <iostream>
#include <string>
#include <vector>
#include <sstream>
#include <cstring>
#include <algorithm>

using namespace std;

int main(){
    string str = "";
    std::vector<string> sentence;
    string temp = "";
    string maxString = "";
    int resultCompare = 0;

    // forbidden symbols
    char characters[] = "0123456789";

    // word of the sentence(vector of characters in a word)
    string word = "";

    // create a stringstream
    stringstream ss;

    // get the sentence string
    getline(cin, str);

    // populate the stringstream
    ss << str;

    // get each vector(word) in the vector of strings(sentence) from the stringstream populated with the sentence
    while(ss >> word) {
        // using #include <cstring> for strlen
        // erase every character that is not allowed (from the forbidden symbols array) from the word(vector of characters)
        // using the erase-remove idiom
        for(size_t j = 0; j < strlen(characters); j++) {
            word.erase(std::remove(word.begin(), word.end(), characters[j]), word.end());
        }
        //push the vector of characters to the sentence vector of strings
        sentence.push_back(word);
    }

    // loop through the vector of strings(sentence)
    for(int i = 0; i < sentence.size(); i++) {
        // set each word to temp string
        temp = sentence[i];
        // compare temp an maxString by size of the strings
        if(temp.size() >= maxString.size()) {
            // compare tema and maxString lexicographically (using #include <algorithm>
            resultCompare = lexicographical_compare(maxString.begin(), maxString.end(), temp.begin(), temp.end());
            // if result is 0 -> first string is equal to second string lexicographically
            // if result is 1 -> first string is bigger to second string lexicographically
            // if result is negative -> first string is smaller than second string lexicographically
            if(resultCompare == 0 || resultCompare == 1) {
                // if strings equal or first string is bigger lexicographically, set maxString to temp(found the biggest string)
                maxString = temp;
            }
        }
    }

    // if vector of allowed chars(word without numbers) was found in the sentence
    // and the it is the biggest after size and lexicographical checks, output the biggest word
    if(!maxString.empty()) {
        cout << maxString << endl;
        // if not output "no noise"
    } else {
        cout << "no noise" << endl;
    }

    return 0;
}