/*
TASK: ldist
LANG: C++
*/

#include <iostream>
#include <cstring>

using namespace std;

#define MAXN 1024

#define MAX( a, b ) ( (a) > (b) ? (a) : (b) )
#define MIN2( a, b ) ( (a) < (b) ? (a) : (b) )
#define MIN( a, b, c ) ( MIN2(a,MIN2(b,c)) )

int F[MAXN][MAXN];

char a[MAXN];
char b[MAXN];

int V[256], D[256][256];

int main()
{
   int i, n, m, j, x, y, w;

   for(i='1'; i<= 'z'; i++ )  {
     for( j = '1'; j <= 'z'; j++ )
            D[i][j] = D[j][i] = 100;
      V[i] = 100;
   }
   cin >> x;

   for( i = 0; i < x; i++ ) {
     char c;
     cin >> c >> w;
     V[c] = w;
   }

   cin >> y;

   for( i = 0; i < y; i++ ) {
     char c1, c2;
     cin >> c1 >> c2 >> w;
     D[c1][c2] = D[c2][c1] = w;
   }

   cin >> a;
   cin >> b;

   n = strlen( a );
   m = strlen( b );

   int sum = 0;

   if( n < m ) {
     for( i = 0; i < n; i++ )
       if( a[i] != b[i] )
         sum += MIN2( D[a[i]][b[i]], V[a[i]] + V[b[i]] );
     sum += ( m - n ) * 100 - 240;
     cout << sum<<"\n";
   }
   else {
     for( i = 0; i < m; i++ )
        if( a[i] != b[i] )
           sum += MIN2( D[a[i]][b[i]], V[a[i]] + V[b[i]] );
     sum += ( m - n ) * 100 - 240;
     cout<<sum<<"\n";
   }

   return 0;
}


   

