{"pre_text": ["the table below reflects the estimated effects on pension expense of certain changes in annual assumptions , using 2014 estimated expense as a baseline .", "table 29 : pension expense 2013 sensitivity analysis change in assumption ( a ) estimated increase/ ( decrease ) to 2014 pension expense ( in millions ) ."], "post_text": ["( a ) the impact is the effect of changing the specified assumption while holding all other assumptions constant .", "our pension plan contribution requirements are not particularly sensitive to actuarial assumptions .", "investment performance has the most impact on contribution requirements and will drive the amount of required contributions in future years .", "also , current law , including the provisions of the pension protection act of 2006 , sets limits as to both minimum and maximum contributions to the plan .", "we do not expect to be required by law to make any contributions to the plan during 2014 .", "we maintain other defined benefit plans that have a less significant effect on financial results , including various nonqualified supplemental retirement plans for certain employees , which are described more fully in note 15 employee benefit plans in the notes to consolidated financial statements in item 8 of this report .", "recourse and repurchase obligations as discussed in note 3 loan sale and servicing activities and variable interest entities in the notes to consolidated financial statements in item 8 of this report , pnc has sold commercial mortgage , residential mortgage and home equity loans directly or indirectly through securitization and loan sale transactions in which we have continuing involvement .", "one form of continuing involvement includes certain recourse and loan repurchase obligations associated with the transferred assets .", "commercial mortgage loan recourse obligations we originate , close and service certain multi-family commercial mortgage loans which are sold to fnma under fnma 2019s delegated underwriting and servicing ( dus ) program .", "we participated in a similar program with the fhlmc .", "our exposure and activity associated with these recourse obligations are reported in the corporate & institutional banking segment .", "for more information regarding our commercial mortgage loan recourse obligations , see the recourse and repurchase obligations section of note 24 commitments and guarantees included in the notes to consolidated financial statements in item 8 of this report .", "residential mortgage repurchase obligations while residential mortgage loans are sold on a non-recourse basis , we assume certain loan repurchase obligations associated with mortgage loans we have sold to investors .", "these loan repurchase obligations primarily relate to situations where pnc is alleged to have breached certain origination covenants and representations and warranties made to purchasers of the loans in the respective purchase and sale agreements .", "residential mortgage loans covered by these loan repurchase obligations include first and second-lien mortgage loans we have sold through agency securitizations , non-agency securitizations , and loan sale transactions .", "as discussed in note 3 in the notes to consolidated financial statements in item 8 of this report , agency securitizations consist of mortgage loan sale transactions with fnma , fhlmc and the government national mortgage association ( gnma ) , while non-agency securitizations consist of mortgage loan sale transactions with private investors .", "mortgage loan sale transactions that are not part of a securitization may involve fnma , fhlmc or private investors .", "our historical exposure and activity associated with agency securitization repurchase obligations has primarily been related to transactions with fnma and fhlmc , as indemnification and repurchase losses associated with fha and va-insured and uninsured loans pooled in gnma securitizations historically have been minimal .", "repurchase obligation activity associated with residential mortgages is reported in the residential mortgage banking segment .", "loan covenants and representations and warranties are established through loan sale agreements with various investors to provide assurance that pnc has sold loans that are of sufficient investment quality .", "key aspects of such covenants and representations and warranties include the loan 2019s compliance with any applicable loan criteria established for the transaction , including underwriting standards , delivery of all required loan documents to the investor or its designated party , sufficient collateral valuation and the validity of the lien securing the loan .", "as a result of alleged breaches of these contractual obligations , investors may request pnc to indemnify them against losses on certain loans or to repurchase loans .", "we investigate every investor claim on a loan by loan basis to determine the existence of a legitimate claim and that all other conditions for indemnification or repurchase have been met prior to the settlement with that investor .", "indemnifications for loss or loan repurchases typically occur when , after review of the claim , we agree insufficient evidence exists to dispute the investor 2019s claim that a breach of a loan covenant and representation and warranty has occurred , such breach has not been cured and the effect of such breach is deemed to have had a material and adverse effect on the value of the transferred loan .", "depending on the sale agreement and upon proper notice from the investor , we typically respond to such indemnification and repurchase requests within 60 days , although final resolution of the claim may take a longer period of time .", "with the exception of the sales agreements associated the pnc financial services group , inc .", "2013 form 10-k 67 ."], "table": [["change in assumption ( a )", "estimated increase/ ( decrease ) to 2014 pension expense ( in millions )"], [".5% ( .5 % ) decrease in discount rate", "$ -2 ( 2 )"], [".5% ( .5 % ) decrease in expected long-term return on assets", "$ 21"], [".5% ( .5 % ) increase in compensation rate", "$ 1"]], "table_ori": [["Change in Assumption (a)", "Estimated Increase/(Decrease) to 2014 Pension Expense (In millions)"], [".5% decrease in discount rate", "$(2)"], [".5% decrease in expected long-term return on assets", "$21"], [".5% increase in compensation rate", "$1"]]}

Question: what is the difference in millions on the pension expense effect of a .5% ( .5 % ) decrease in expected long-term return on assets compared to a .5% ( .5 % ) increase in compensation rate?
Evidence:
table_2: change in assumption ( a ) the .5% ( .5 % ) decrease in expected long-term return on assets of estimated increase/ ( decrease ) to 2014 pension expense ( in millions ) is $ 21 ;
table_3: change in assumption ( a ) the .5% ( .5 % ) increase in compensation rate of estimated increase/ ( decrease ) to 2014 pension expense ( in millions ) is $ 1 ;
Program: subtract(21, 1)
Answer:
str_answer: 20
exe_answer: 20