def test_xvi_to_16():
assert roman_to_integer("XVI") == 16
def test_ii_to_2():
assert roman_to_integer("II") == 2
def test_mcmxciv_to_1994():
assert roman_to_integer("MCMXCIV") == 1994
def test_xv_to_15():
assert roman_to_integer("XV") == 15
def test_xlv_to_45():
assert roman_to_integer("XLV") == 45
def test_xc_to_90():
assert roman_to_integer("XC") == 90
def test_ix_to_9():
assert roman_to_integer("IX") == 9
def test_xx_to_20():
assert roman_to_integer("XX") == 20
def test_i_to_1():
assert roman_to_integer("I") == 1
def test_viii_to_8():
assert roman_to_integer("VIII") == 8
def test_vi_to_6():
assert roman_to_integer("VI") == 6
def test_v_to_5():
assert roman_to_integer("V") == 5
def test_iv_to_4():
assert roman_to_integer("IV") == 4
def test_xviii_to_18():
assert roman_to_integer("XVIII") == 18
def test_x_to_10():
assert roman_to_integer("X") == 10
def test_xix_to_19():
assert roman_to_integer("XIX") == 19
def test_xi_to_11():
assert roman_to_integer("XI") == 11
def test_xxx_to_30():
assert roman_to_integer("XXX") == 30
def test_xiii_to_13():
assert roman_to_integer("XIII") == 13
def test_lviii_to_58():
assert roman_to_integer("LVIII") == 58
def test_xiv_to_14():
assert roman_to_integer("XIV") == 14
def test_c_to_100():
assert roman_to_integer("C") == 100
def test_mcm_to_1900():
assert roman_to_integer("MCM") == 1900