How to get sum of all the order values for a given id of a column in matrix

i have 2 columns and 10 rows

1    10
2    29
2    34
2    79
3    11
3    20
3    11
4    9
4    1
5    10

i want the add numbers having same value in first column The answer i want is using loop or any other operation

1  10
2  142
3  42
4  10
5  10

Answer 1

[Azzi Abdelmalek]

A=[1    10;2    29;2    34;2    79;3    11;3    20;3    11;4    9;4    1;5    10]
out=[unique(A(:,1)) accumarray(A(:,1),A(:,2))]

[Mitul saraiya]

Actually i have to work on a matrix with 2 columns but more than 100 rows when i tried using accumarray it gives error as Error using horzcat Dimensions of matrices being concatenated are not consistent.

Error in mm (line 26) out=[unique(mannu(:,1)) accumarray(mannu(:,1),mannu(:,2))];

mannu is the matrix with 2 columns and 100 rows