int main(){
int i, j, x=0;
for(i=1;i<5;++i)
    for(j=0;i<j;++j){
        switch(i+j-1){
            case -1:
            case 0:
            x+=1;
            break;
            case 1:
            case 2:
            case 3:
            x+=2;
            default:
            x+=3;

        }
        printf("%d",x);

        }

   printf("nx=%d",x);
   return 0;
}