def shu(n):
    r = 0;
    if n == 1:
       r = 1;
    else:
       r = shu(n - 1) + n - 1 
    return r;

i = 1
s = 0
while s < 5000:
    s += shu(i)
    i += 1

print(s)
/**************************************************************
	Problem: 1146
	User: admin
	Language: Python
	Result: Accepted
	Time:50 ms
	Memory:34480 kb
****************************************************************/