S.No. ID SEM TCP
1 R111010 E1S1 158
2 R111010 E1S1 158
3 R111010 E1S1 158
4 R111010 E1S2 175
5 R111010 E1S2 175
6 R111010 E1S2 175
7 R111010 E2S1 182
1 R111010 E2S1 182
2 R111010 E2S1 182
3 R111010 E2S2 136
4 R111010 E2S2 136
5 R111010 E2S2 136

I need to sum the TCP column by avoiding duplicate entries in ID and SEM. For a single ID, different TCP are there in different SEM. I need to sum the TCP of that student in each SEM by avoiding /neglecting duplicates. Please help me with excel 2010/2007 formula.