#include <stdio.h>
#include <string.h>

int main()
{
	char s[100];
	while(scanf("%s",s) != EOF)
	{
		char *p = s;
		while(*p)
		{
			if(*p >= 'A' && *p <= 'Z')
			{
				printf("_%c",*p+32);
			}
			else printf("%c",*p);
			p++;
		}
		printf("\n");
	}
	return 0;
}