style: number 
min_depth: 1 
max_depth: 6

# Returns true if target is reachable from src within max_depth
def IDDFS(src, target, max_depth):
    for limit in range(max_depth)
       if DLS(src, target, limit):
           return True
    return False   
 
def DLS(src, target, limit):
    if (src == target)
        return true;
 
    # If reached the maximum depth, stop recursing.
    if (limit <= 0)
        return false;   
 
    for i in src.neighbors():
        if DLS(i, target, limit-1)             
            return true
 
    return false