10+11+12+13+14+15+16+17+18+19=145
20+21+22+23+24+25+26+27+28+29=245
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26+27+28+29
+30+31+32+33+34+35+36+37+38+39+40=820
10+11+12+13+14+15+16+17+18+19=145
20+21+22+23+24+25+26+27+28+29=245
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26+27+28+29
+30+31+32+33+34+35+36+37+38+39+40=820