#include<cstdio>

using namespace std;

int main() {
    char i, j;
    scanf("%d", &i);
    switch (i) {
        case 'm':
            printf("monday\n");
            break;
        case 'w':
            printf("wednesday\n");
            break;
        case 'f':
            printf("friday\n");
            break;
        case 't':
            scanf("%d", &j);
            if (j == 'u') {
                printf("tuesday\n");
                break;
            }
            if (j == 'h') {
                printf("thursday\n");
                break;
            }
        case 's':
            scanf("%d", &j);
            if (j == 'a') {
                printf("saturday\n");
                break;
            }
            if (j == 'u') {
                printf("sunday\n");
                break;
            }
        default :
            printf("error\n");
            break;
    }
    return 0;
}