How to compare multiple columns in excel?

i have two sheets having data like this

sheet1 :
**A**   **B**         **C**
752       A
752       E
752       N
984       G1
984       G2
4471      U1
4471      U2
4471      U4
4471      U5
4471      U7
4471      U8

sheet2:
**A**   **B**    **C**
132       G      69092
227       G      29400
227       G1    2378
292       G     2088
426       G     14419
752       A     180829
752       E     719404
752       N     602180
1173      G     7361
1173    G1  13083
1619    US  108
5804    N   701
5804    SG  8
5819    CA  24
6333    AE  218

What i want is, i need compare sheet1 and sheet2 , if sheet1 A and B columns match with sheet2 's A and B columns then i want the value C (column in sheet2) to be placed in sheet1 column C.

Please help me, i know how to compare only one column with other column by using vlookup, but here i want to compare two columns at a time.

Thanks in advance

Quick and dirty way, insert one more column (X) on both sheets then add formula to concat (A) and (B). Now, use this new column (X) to vlookup the value of column (C)