Why does this give runtime error #8 .
n = int(raw_input())
k = int(raw_input())
dp = [[-1 for x in xrange(15)]for y in xrange(1910)]
def solve(index,prev) :
    if(index > n ) :
        return 1
    if(dp[index][prev] != -1) :
        return dp[index][prev]
    res = 0
    start = 0
    if(index == 1) :
        start = 1
    for i in xrange(start,k) :
        if(prev == 0 and i == 0) :
            continue
        res = res + solve(index+1,i)
    dp[index][prev] = res ;
    return  res
print solve(1,0)

Same for me, solution is python3.

You have to check for recursion depth exceeded. Do it iterative.