657 B | 657 chars
import sys
from math import sqrt, pi, sin, factorial, ceil, floor
from datetime import datetime, timedelta
sys.setrecursionlimit(10**7)
BLANK = " "
#inp = input
inp = lambda : sys.stdin.readline().rstrip()
mii = lambda x = BLANK : [*map(int,inp().split(x))]
mfi = lambda x = BLANK : [*map(float,inp().split(x))]
ii = lambda : int(inp())
fi = lambda : float(inp())
p = print
def solve():
n, s = inp().split()
ans = 0
for i in range(int(n)):
k, cnt = inp().split()
l = k.split("_")
cnt = int(cnt)
if s in l:
ans += cnt
p(ans)
if __name__ == "__main__":
tc = 1
for t in range(1, tc+1):
ret = solve()