Thanks for answer. I have bits of size 50, so I need bigint/long long int. Problem is in while loop. When I use bitand(a,b) and numbers of digits of a and b both are 18-19, the system enters endless loop I think. Bigint maximum value is 19 digits long.I have mistakes in code when using unsigned int and I changed, but same problem. As I know from data types page, monetdb uses only signed integers, so I use only signed ones. Any ideas why does it hang on 18-19 digits and not on 1-17 digits long numbers?