e-olymp
Competitions

PP2. Week 4: March 29 - April 4

Sum of positive in matrix

Given matrix of size n * n. Find the sum of its positive elements.

Input

First line contains number n (1n100). Next lines contains the n * n matrix. All numbers in the matrix are no more than 100 by absolute value.

Output

Print the sum of positive numbers in the matrix.

Time limit 1 second
Memory limit 128 MiB
Input example #1
3
4 -2 5
1 -4 -12
0 1 -3
Output example #1
11