№17 — #17137

t = open('17_17133+.txt')
s = [int(n) for n in t.readlines()]
d = []
h = max([x for x in s if 100 <= x <= 999])
for i in range(len(s)-1):
    if (100 <= s[i] <= 999) or (100 <= s[i+1] <= 999):
        if s[i] + s[i+1] < h:
            d.append(s[i] + s[i+1])
print(len(d))