x = [1,0,1,2,10,5]
k = 3
prefix = [0] * len(x)
prefix[0] = x[0]
for i in range(1, len(x)):
prefix[i] = prefix[i-1]+x[i]
count = 0
for j in range(1, len(x)):
for i in range(0, j):
if prefix[i] == prefix[j]-k:
count+=1
print(count)
eCA9IFsxLDAsMSwyLDEwLDVdCmsgPSAzCnByZWZpeCA9IFswXSAqIGxlbih4KQoKcHJlZml4WzBdID0geFswXQoKZm9yIGkgaW4gcmFuZ2UoMSwgbGVuKHgpKToKCXByZWZpeFtpXSA9IHByZWZpeFtpLTFdK3hbaV0KCmNvdW50ID0gMApmb3IgaiBpbiByYW5nZSgxLCBsZW4oeCkpOgoJZm9yIGkgaW4gcmFuZ2UoMCwgaik6CgkJaWYgcHJlZml4W2ldID09IHByZWZpeFtqXS1rOgoJCQljb3VudCs9MQpwcmludChjb3VudCk=