1 import java.util.Scanner; 2 import java.math.BigInteger; 3  4 public class Main { 5     public static void main(String[] args) { 6         Scanner cin = new Scanner(System.in); 7         int n; 8         int i, j, k, tmp; 9         int top;10         boolean flag;11         int t = 0;12         while (cin.hasNext()) {13             n = cin.nextInt();14             for (i=0; i<n; ++i)15                 buf[i] = cin.next();16             flag = true;17             if ((n&1) == 0)18                 flag = false;19             for (i=0; flag&&i<n; ++i) {20                 if ((i & 1) == 1) {21                     if (buf[i].charAt(0)!=‘+‘ && buf[i].charAt(0)!=‘*‘)22                         flag = false;23                 } else {24                     if (buf[i].charAt(0)==‘+‘ || buf[i].charAt(0)==‘*‘)25                         flag = false;26                 }27             }28             System.out.printf("Case %d: ", ++t);29             if (flag==false || n==0) {30                 System.out.println("Invalid Expression!");31                 continue;32             }33             top = 0;34             bi[top++] = new BigInteger(buf[0]);35             i = 1;36             while (i < n) {37                 if (buf[i].charAt(0) == ‘*‘) {38                     BigInteger a = bi[top-1];39                     BigInteger b = new BigInteger(buf[i+1]);40                     bi[top-1] = a.multiply(b);41                 } else {42                     bi[top++] = new BigInteger(buf[i+1]);43                 }44                 i += 2;45             }46             BigInteger sum = BigInteger.ZERO;47             for (i=0; i<top; ++i) {48                 sum = sum.add(bi[i]);49             }50             System.out.println(sum.toString());51         }52     }53     54     final public static int MAXN = 25;55     public static String[] buf = new String[MAXN];56     public static BigInteger[] bi = new BigInteger[MAXN];57 }