a = [1, 2, 3, -12, 2, 3, 4, 5, 1, 231, -1, 1, 3]
print sum(a[filter(lambda _: _[1] < 0, enumerate(a))[0][0] + 1:filter(lambda _: _[1] < 0, enumerate(a))[1][0]])
YSA9IFsxLCAyLCAzLCAtMTIsIDIsIDMsIDQsIDUsIDEsIDIzMSwgLTEsIDEsIDNdCnByaW50IHN1bShhW2ZpbHRlcihsYW1iZGEgXzogX1sxXSA8IDAsIGVudW1lcmF0ZShhKSlbMF1bMF0gKyAxOmZpbHRlcihsYW1iZGEgXzogX1sxXSA8IDAsIGVudW1lcmF0ZShhKSlbMV1bMF1dKQo=