N = int(input())
A = list(map(int,input().split()))
diff = [A[i+1] - A[i] for i in range(N-1)]

def rle(S):
    count = 0
    now = None
    ret = []
    for i in range(len(S)):
        if(now != S[i]):
            if(now is not None):ret.append((now,count))
            now = S[i]
            count = 1
        else:
            count += 1
    ret.append((now,count))
    return ret

rl = rle(diff)
ans = 0
for a,b in rl:
    if(a == 1):ans += b*(b+1)//2
print(ans)