#include<stdio.h>
#pragma warning(disable:4996)
int C, N, M, arr[201][21];
int prefer[21];
int price[21];
int main(){
    int i, j;
    scanf("%d %d", &N, &M);
    for (i = 1; i <= N; i++){
        scanf("%d %d", &price[i], &prefer[i]);
    }
    for (i = 1; i <= M/100; i++){//잔액
        for (j = 1; j <= N; j++){//먹는 음식의 수
            if (i >= price[j] / 100){
                if (arr[i - price[j] / 100][j - 1] + prefer[j] >= arr[i][j - 1])
                    arr[i][j] = arr[i - price[j] / 100][j - 1] + prefer[j];
                else
                    arr[i][j] = arr[i][j - 1];
            }
            else
                arr[i][j] = arr[i][j - 1];
        }
    }
    printf("%d\n", arr[M / 100][N]);
    return 0;
}