# Hard class group of Carlo
# Qx, x  = PolynomialRing(FlintQQ, "x");
# f = x^4-x^3-378*x^2+2081*x-67;
# K, a = number_field(f);
# C = cyclotomic_extension(K, 7)
# K = absolute_field(C);

f = x^24-2*x^23-2266*x^22+15510*x^21+2122618*x^20-25022546*x^19-994971857*x^18+17780224498*x^17+204666064586*x^16-6330369896072*x^15+6277040017522*x^14+1024499591458410*x^13-9491657191588213*x^12-25302258130671850*x^11+1000337781397362862*x^10-7709908154554062116*x^9+28992452711792779249*x^8-52916196926862805102*x^7+29422192713421978873*x^6+13659727327936090732*x^5+15671251179023563628*x^4+15074383085029309092*x^3+24075625195314205057*x^2-10144837465570789446*x+64250789525986279259

Add some class group example of Carlo
Add some class group example of Carlo
