>>352
#include<iostream>
#include<string>

using namespace std;

int main(void){
string str, str_new;

cout << "文字列を入力してください. ";
getline(cin, str);
cout << "文字列の長さは " << str.size() << " です." << endl;

for(int i=0;i<str.size();i++){
if(isupper(str[i])) str_new+=tolower(str[i]);
else if(islower(str[i])) str_new+=toupper(str[i]);
else if(isdigit(str[i])) str_new+=str[i];
}
cout << "変換された文字列: " << str_new << endl;
return 0;
}