If you want a few similar problems, in ascending order of difficulty, try #81 through #83: https://projecteuler.net/problem=81 https://projecteuler.net/problem

If you want a few similar problems, in ascending order of difficulty, try #81 through #83: https://projecteuler.net/problem=81 https://projecteuler.net/problem=81 https://projecteuler.net/problem=82 https://projecteuler.net/problem=82 https://projecteuler.net/problem=83 https://projecteuler.net/problem=83