Assuming the numbers are stand alone values in column D...
=SUMIFS(D1:D7,A1:A7,"Athif",B1:B7,"America")
=SUMPRODUCT(--(A1:A7="Athif"),--(B1:B7="America"),D1:D7)
At this point, you also might want to consider creating a PivotTable to quickly get sums/counts of all the different countries/people visits.