#include <iostream>
#include <cstring>
using namespace std;
int main() {
char var[ 2001];
while(cin.getline(var, 2001)) {
int lg = strlen(var);
for (int i = 0; i < lg; ++i) {
if (var[i]>= 'A' && var[i] <= 'Z') {
cout << '_' << (char)(var[i] + 32);
} else {
cout << var[i];
}
}
cout << '\n';
}
return 0;
}
I2luY2x1ZGUgPGlvc3RyZWFtPgojaW5jbHVkZSA8Y3N0cmluZz4KdXNpbmcgbmFtZXNwYWNlIHN0ZDsKCmludCBtYWluKCkgewoJY2hhciB2YXJbIDIwMDFdOwoJd2hpbGUoY2luLmdldGxpbmUodmFyLCAyMDAxKSkgewoJCWludCBsZyA9IHN0cmxlbih2YXIpOwoJCWZvciAoaW50IGkgPSAwOyBpIDwgbGc7ICsraSkgewoJCQlpZiAodmFyW2ldPj0gJ0EnICYmIHZhcltpXSA8PSAnWicpIHsKCQkJCWNvdXQgPDwgJ18nIDw8IChjaGFyKSh2YXJbaV0gKyAzMik7CgkJCX0gZWxzZSB7CgkJCQljb3V0IDw8IHZhcltpXTsKCQkJfQoJCX0KCQljb3V0IDw8ICdcbic7Cgl9CglyZXR1cm4gMDsKfQ==