/* by EXISTENCE ( Morut Razvan - Liceul Teoretic "Vasile Goldis", Arad) */

#include <stdio.h>

FILE *f,*g;
long v[17][17];

 int citeste (int &a, int &b) ;
 int flip (int a, int b) ;
 int scrie (long S) ;

int main()
{
 int a,b ;
 long S ;
 citeste(a,b) ;
 S=flip(a,b);
 scrie(S);
 return 0 ;
}

int citeste (int &a, int &b)
{
 int i,j ;
 f=fopen ( "flip.in" , "r" ) ;
 fscanf(f,"%d %d\n", &a, &b) ;
 for(i=0;i<a;i++)
  {
   for(j=0;j<b;j++)
    fscanf(f,"%ld ", &v[i][j]) ;
   if(i<a) fscanf(f,"\n") ;
  }
 fclose(f) ;
 return 0 ;
}

int flip (int a, int b)
{
 int i,j ;
 long S=0 ;
 for(i=0;i<a;i++)
  for(j=0;j<b;j++)
   if(v[i][j]>0) S+=v[i][j];
 return(S) ;
}

int scrie(long S)
{
 g=fopen ( "flip.out" , "w" ) ;
 fprintf(g,"%ld", S);
 fclose(g);
 return 0;
}