void du3(int a[][5],int bb2)                   
{
    int i,j;
    int x,y;
    int b[4][5];
    FILE *pf;
    FILE *pf1;
    if((pf=fopen("e:\\FILE522_abA.txt","r"))==NULL)  
    {
        printf("Cannot open file!");
        return;
    }
    for(i=0;i<bb2;i++)
        for(j=0;j<5;j++)
        {
            fscanf(pf,"%4d",&a[i][j]);                
            fscanf(pf,"\n");
        }
        fclose(pf);


    if((pf1=fopen("e:\\FILE522_C.txt","r"))==NULL)  
    {
        printf("Cannot open file!");
        return;
    }
    for(x=0;x<4;x++)
        for(y=0;y<5;y++)
        {
            fscanf(pf1,"%4d",&b[i][j]);                
            fscanf(pf1,"\n");
        }
        fclose(pf1);

}