1 /*
2 解方程组
3 */
4 // include file
5 #include <cstdio>
6 #include <cstdlib>
7 #include <cstring>
8 #include <cmath>
9 #include <cctype>
10 #include <ctime>
11
12 #include <iostream>
13 #include <sstream>
14 #include <fstream>
15 #include <iomanip>
16 #include <bitset>
17
18 #include <algorithm>
19 #include <string>
20 #include <vector>
21 #include <queue>
22 #include <set>
23 #include <list>
24 #include <functional>
25
26 using namespace std;
27
28 // typedef
29 typedef long long LL;
30 typedef unsigned long long ULL;
31 typedef __int64 Bint;
32
33 //
34 #define read freopen("in.txt","r",stdin)
35 #define write freopen("out.txt","w",stdout)
36 #define FORi(a,b,c) for(int i=(a);i<(b);i+=c)
37 #define FORj(a,b,c) for(int j=(a);j<(b);j+=c)
38 #define FORk(a,b,c) for(int k=(a);k<(b);k+=c)
39 #define FORp(a,b,c) for(int p=(a);p<(b);p+=c)
40 #define FORii(a,b,c) for(int ii=(a);ii<(b);ii+=c)
41 #define FORjj(a,b,c) for(int jj=(a);jj<(b);jj+=c)
42 #define FORkk(a,b,c) for(int kk=(a);kk<(b);kk+=c)
43
44 #define FF(i,a) for(int i=0;i<(a);i++)
45 #define FFD(i,a) for(int i=(a)-1;i>=0;i--)
46
47 #define Z(a) (a<<1)
48 #define Y(a) (a>>1)
49
50 const double eps = 1e-6;
51 const double INFf = 1e10;
52 const int INFi = 1000000000;
53 const double Pi = acos(-1.0);
54
55 template<class T> inline T sqr(T a){return a*a;}
56 template<class T> inline T TMAX(T x,T y)
57 {
58 if(x>y) return x;
59 return y;
60 }
61 template<class T> inline T TMIN(T x,T y)
62 {
63 if(x<y) return x;
64 return y;
65 }
66 template<class T> inline void SWAP(T &x,T &y)
67 {
68 T t = x;
69 x = y;
70 y = t;
71 }
72 template<class T> inline T MMAX(T x,T y,T z)
73 {
74 return TMAX(TMAX(x,y),z);
75 }
76
77
78 // code begin
79 int N,M,sum;
80 char nm[50];
81 int main()
82 {
83 read;
84 write;
85 //3M-总分
86 int a;
87 while(scanf("%d %d",&N,&M)!=-1)
88 {
89 if(N+M==0) break;
90 sum = 0;
91 while(N--)
92 {
93 scanf("%s %d",nm,&a);
94 sum += a;
95 }
96 printf("%d\n",3*M-sum);
97 }
98 return 0;
99 }
