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

int main() {
    char n[11];
    scanf("%s", n);
    switch(strlen(n))) {
        case 5: puts("wan"); break;
        case 6: puts("shi wan"); break;
        case 7: puts("bai wan"); break;
        case 8: puts("qian wan"); break;
        case 9: puts("yi"); break;
        case 10: puts("shi yi"); break;
        default: puts("invalid");
    }
    return 0;
}
/**************************************************************
	Problem: 1322
	User: fuhoubin
	Language: C++
	Result: Compile Error
****************************************************************/