for(int i=0; i<MAXN; i++){

for(int j=0; j<MAXN; j++){

dp[i][j] = INF;

}

}

dp[0][1] = 0;

for(int level=1; level<=N; level++){

for(int cur_node = 1; cur_node<=MAXN; cur_node++){

for(int pre_node =1; pre_node<=MAXN; pre_node++){

if(g[level][cur_node][pre_node] != INF){

dp[level][cur_node] = min(dp[level][cur_node], dp[level-1][pre_node] + g[level][cur_node][pre_node]);

}

}

}

}

int ans = INF;

for(int i=1; i<MAXN; i++){

ans = min(ans, dp[N][i]);

}

cout<<ans<<endl;

cin>>N;

for(int i=0; i<MAXN; i++)for(int j=0; j<MAXN; j++){

for(int k=0; k<MAXN; k++){

g[i][j][k] = INF;

}

}

for(int level=1; level<=N; level++){

int K;

cin>>K;

for(int k=1; k<=K; k++){

while(1){

int a, b;

cin>>a;

if(a==0)break;

cin>>b;

//cout<<"a = "<<a<<" b = "<<b<<endl;

//cout<<"g["<<level<<"]["<<k<<"]["<<a<<"] = "<<b<<endl;

g[level][k][a] = b;

}

}

if(level<N){

string t;

cin>>t;

//cout<<"now setting "<<t<<endl;

}

}

work();

return 0;