1 #include <bits/stdc++.h> 2 using namespace std; 3 #define pb push_back 4 #define _for(i,a,b) for(int i = (a);i < (b);i ++) 5 #define INF 100000003 6 #define ll long long 7 inline ll read() 8 { 9 ll ans = 0; 10 char ch = getchar(), last = ' '; 11 while(!isdigit(ch)) last = ch, ch = getchar(); 12 while(isdigit(ch)) ans = (ans << 1) + (ans << 3) + ch - '0', ch = getchar(); 13 if(last == '-') ans = -ans; 14 return ans; 15 } 16 inline void write(ll x) 17 { 18 if(x < 0) x = -x, putchar('-'); 19 if(x >= 10) write(x / 10); 20 putchar(x % 10 + '0'); 21 } 22 int n; 23 int a[40][40]; 24 int main() 25 { 26 while(~scanf("%d",&n)) 27 { 28 if(!n) 29 break; 30 _for(i,1,n+1) 31 _for(j,1,n+1) 32 if(i<j) 33 a[i][j] = a[j][i] = read(); 34 35 36 int ans = 0; 37 _for(i,3,n+1) 38 { 39 int t = INT_MAX; 40 _for(j,2,i) 41 { 42 t = min(t,(a[1][i]+a[i][j]-a[1][j])/2); 43 } 44 ans += t; 45 } 46 printf("%d ",ans+a[1][2]); 47 } 48 49 return 0; 50 }