credit rating fall below investment grade , the value of the outstanding undivided interest held by investors would be reduced , and , in certain cases , the investors would have the right to discontinue the facility . the railroad collected approximately $ 20.1 billion and $ 18.8 billion of receivables during the years ended december 31 , 2012 and 2011 , respectively . upri used certain of these proceeds to purchase new receivables under the facility . the costs of the receivables securitization facility include interest , which will vary based on prevailing commercial paper rates , program fees paid to banks , commercial paper issuing costs , and fees for unused commitment availability . the costs of the receivables securitization facility are included in interest expense and were $ 3 million , $ 4 million and $ 6 million for 2012 , 2011 and 2010 , respectively . the investors have no recourse to the railroad 2019s other assets , except for customary warranty and indemnity claims . creditors of the railroad do not have recourse to the assets of upri . in july 2012 , the receivables securitization facility was renewed for an additional 364-day period at comparable terms and conditions . subsequent event 2013 on january 2 , 2013 , we transferred an additional $ 300 million in undivided interest to investors under the receivables securitization facility , increasing the value of the outstanding undivided interest held by investors from $ 100 million to $ 400 million . contractual obligations and commercial commitments as described in the notes to the consolidated financial statements and as referenced in the tables below , we have contractual obligations and commercial commitments that may affect our financial condition . based on our assessment of the underlying provisions and circumstances of our contractual obligations and commercial commitments , including material sources of off-balance sheet and structured finance arrangements , other than the risks that we and other similarly situated companies face with respect to the condition of the capital markets ( as described in item 1a of part ii of this report ) , there is no known trend , demand , commitment , event , or uncertainty that is reasonably likely to occur that would have a material adverse effect on our consolidated results of operations , financial condition , or liquidity . in addition , our commercial obligations , financings , and commitments are customary transactions that are similar to those of other comparable corporations , particularly within the transportation industry . the following tables identify material obligations and commitments as of december 31 , 2012 : payments due by december 31 , contractual obligations after millions total 2013 2014 2015 2016 2017 2017 other .

Table:
contractual obligationsmillions | total | payments due by december 31 2013 | payments due by december 31 2014 | payments due by december 31 2015 | payments due by december 31 2016 | payments due by december 31 2017 | payments due by december 31 after2017 | payments due by december 31 other
debt [a] | $ 12637 | $ 507 | $ 904 | $ 632 | $ 769 | $ 900 | $ 8925 | $ -
operating leases [b] | 4241 | 525 | 466 | 410 | 375 | 339 | 2126 | -
capital lease obligations [c] | 2441 | 282 | 265 | 253 | 232 | 243 | 1166 | -
purchase obligations [d] | 5877 | 3004 | 1238 | 372 | 334 | 213 | 684 | 32
other post retirement benefits [e] | 452 | 43 | 44 | 45 | 45 | 46 | 229 | -
income tax contingencies [f] | 115 | - | - | - | - | - | - | 115
total contractualobligations | $ 25763 | $ 4361 | $ 2917 | $ 1712 | $ 1755 | $ 1741 | $ 13130 | $ 147
[a] excludes capital lease obligations of $ 1848 million and unamortized discount of $ ( 365 ) million .
includes an interest component of $ 5123 million .
[b] includes leases for locomotives , freight cars , other equipment , and real estate .
[c] represents total obligations , including interest component of $ 593 million .
[d] purchase obligations include locomotive maintenance contracts ; purchase commitments for fuel purchases , locomotives , ties , ballast , and rail ; and agreements to purchase other goods and services .
for amounts where we cannot reasonably estimate the year of settlement , they are reflected in the other column .
[e] includes estimated other post retirement , medical , and life insurance payments , payments made under the unfunded pension plan for the next ten years .
[f] future cash flows for income tax contingencies reflect the recorded liabilities and assets for unrecognized tax benefits , including interest and penalties , as of december 31 , 2012 .
for amounts where the year of settlement is uncertain , they are reflected in the other column. .

Question: what is the principal portion of total capital lease obligations , in millions?
Answer: 1848
Calculation: subtract(2441, 593)