'#sec:Main ? "Easter by the method of ";cat(1);"Butcher";cat(-1) 10 input "Enter a year : ",yr if yr=0 then 99 ta=yr%19 tb=yr\100 tc=yr%100 td=tb\4 te=tb%4 tf=(tb+8)\25 tg=(tb-tf+1)\3 th=(19*ta+tb-td-tg+15)%30 ti=tc\4 tk=tc%4 tl=(32+2*te+2*ti-th-tk)%7 tm=(ta+11*th+22*tl)\451 day=th+tl-7*tm+114 mon=day\31 day=day%31+1 if mon=3 then ? "Sunday, March ";day;", ";yr else ? "Sunday, April ";day;", ";yr fi goto 10 99 end '