#include<stdio.h>
int i,k,n,a[101][101],min=10001,s;
FILE *in=fopen("cc.in","rt"),*out=fopen("cc.out","wt");
int main()
{
	fscanf(in,"%d",&n);
	for(i=1;i<=n;i++)
	{
		for(k=1;k<=n;k++)
		{
			fscanf(in,"%d",&a[i][k]);
			if(min>=a[i][k])
				min=a[i][k];
		}
		s+=min;
		min=10001;
	}
	fprintf(out,"%d",s);
	return 0;
}