#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>

using namespace std;
long long int aH, aM, aPH, aPM;
long long int bH, bM, bPH, bPM;
int dan, H, M;
char z;
char ulaz[6];
long long k;
int main(void){
    cin >> ulaz;
    aH=(ulaz[0]-'0')*10+ulaz[1]-'0';
    aM=(ulaz[3]-'0')*10+ulaz[4]-'0';
    cin >> ulaz;
    bH=(ulaz[0]-'0')*10+ulaz[1]-'0';
    bM=(ulaz[3]-'0')*10+ulaz[4]-'0';
    cin >> ulaz;
    aPH=(ulaz[0]-'0')*10+ulaz[1]-'0';
    aPM=(ulaz[3]-'0')*10+ulaz[4]-'0';
    cin >> ulaz;
    bPH=(ulaz[0]-'0')*10+ulaz[1]-'0';
    bPM=(ulaz[3]-'0')*10+ulaz[4]-'0';


    int aa=aH*60+aM;
    int ap=aPH*60+aPM;
    int ba=bH*60+bM;
    int bp=bPH*60+bPM;
    int t=1;
    while(t){
        k++;
        if(aa==ba) {
        t=0;}
        else if(aa<ba) aa+=ap;
        else if(ba<aa) ba+=bp;
        if(k=90000000) t=0;
    }

    if(k=90000000){
        printf("nikad\n");
        return 0;
    }

    while(aa>=1440){
        aa-=1440;
        dan++;
        if(dan==7) dan=0;
    }
    while(aa>=60){
        aa-=60;
        H++;
    }

    M=aa;

    switch(dan){
        case 0:
        printf("subota\n");
        break;

        case 1:
        printf("nedjelja\n");
        break;

        case 2:
        printf("ponedjeljak\n");
        break;

        case 3:
        printf("utorak\n");
        break;

        case 4:
        printf("srijeda\n");
        break;

        case 5:
        printf("cetvrtak\n");
        break;

        case 6:
        printf("nedjelja\n");
        break;
    }

    if(H<10) printf("0%d:", H);
    else printf("%d:", H);
    if(M<10) printf("0%d\n", M);
    else printf("%d\n", M);




    return 0;
}