#include <iostream>#include <cstdlib>#include <cstring>#include <cstdio>using namespace std;string st;int main(){ cin >> st; bool java = false; bool cpp = false; if (st[0] == '_') { cout << "Error!" << endl; return 0; } for (int i = 0; i < st.length(); i++) if (st[i] >= 'A' && st[i] <= 'Z') { if (i == 0) { cout << "Error!" << endl; return 0; } java = true; break; } if (st.find('_') != string::npos) cpp = true; if (cpp && java) { cout << "Error!" << endl; return 0; } if (cpp) { if (st.find("__") != string::npos || st[st.length() - 1] == '_') { cout << "Error!" << endl; return 0; } for (int i = 0; i < st.length(); i++) if (st[i] == '_') { st.erase(i, 1); st[i] = st[i] - 'a' + 'A'; } } else { for (int i = 0; i < st.length(); i++) if (st[i] >= 'A' && st[i] <= 'Z') { st[i] = st[i] - 'A' + 'a'; st.insert(i, "_"); } } cout << st << endl; return 0;}
