import std.stdio:writeln; const int N = 5; static int count = 0; void find_combinations(int[N] arr, int index, int num, int reduced_num) { if(reduced_num < 0) return; if(reduced_num == 0) { count++; return; } int prev = index == 0 ? 1 : arr[index-1]; for(int i = prev; i <= num; ++i) { arr[index] = i; find_combinations(arr,index+1,num,reduced_num-i); } } void main() { int[N] arr; find_combinations(arr,0,N,N); writeln(count); }