#include<cstdio>
#define MAX 1000000000

int main(void){
    char day[7][20]={"subota","nedjelja","ponedjeljak","utorak","srijeda","cetvrtak","petak"};
    int h,m;
    int b1,b2,p1,p2;
    scanf("%d:%d",&h,&m);
    b1=h*60+m;
    if(!b1)b1=24*60;
    scanf("%d:%d",&h,&m);
    b2=h*60+m;
    if(!b2)b2=24*60;
    scanf("%d:%d",&h,&m);
    p1=h*60+m;
    scanf("%d:%d",&h,&m);
    p2=h*60+m;
    int t1=b1,t2=b2;
    do{
        while(t1<t2)t1+=p1;
        while(t2<t1)t2+=p2;
    }while(t1-t2 != b1-b2 && t1!=t2 && t1<MAX);
    if(t1!=t2)printf("nikad\n");
    else {
        printf("%s\n",day[(t1/(24*60))%7]);
        if((t1%(24*60)/60)<10)printf("0");
        printf("%d:",t1%(24*60)/60);
        if((t1%(24*60)%60)<10)printf("0");
        printf("%d\n",t1%(24*60)%60);
    }
    return 0;
}