View Compilation Error

0_0_14624414_713.cpp: In function 'int main()':
0_0_14624414_713.cpp:96:29: error: 'u' was not declared in this scope
    if (d==1 && !S.count(seq[u]) {
                             ^
0_0_14624414_713.cpp:96:33: error: expected ')' before '{' token
    if (d==1 && !S.count(seq[u]) {
                                 ^