# Sum of positive in matrix

Execution time limit is 1 second Runtime memory usage limit is 128 megabytes Matrix of size $n⋅n$ is given. Find the sum of its positive elements.

## Input

First line contains number $n(1≤n≤100)$. 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.

## Examples