Main.cc: In function ‘int main()’: Main.cc:27:12: error: missing template arguments before ‘left’ vector left(n, 1LL), right(n, 1LL); ^~~~ Main.cc:35:24: warning: pointer to a function used in arithmetic [-Wpointer-arith] right[j] = (right[j] + left[i]) % MOD; ^ Main.cc:35:36: warning: pointer to a function used in arithmetic [-Wpointer-arith] right[j] = (right[j] + left[i]) % MOD; ^ Main.cc:35:46: warning: pointer to a function used in arithmetic [-Wpointer-arith] right[j] = (right[j] + left[i]) % MOD; ^ Main.cc:35:38: error: invalid operands of types ‘std::ios_base&(std::ios_base&)’ and ‘std::ios_base&(std::ios_base&)’ to binary ‘operator+’ right[j] = (right[j] + left[i]) % MOD; ~~~~~~~~~^~~~~~~~~ Main.cc:37:23: warning: pointer to a function used in arithmetic [-Wpointer-arith] left[i] = (right[j] + left[i]) % MOD; ^ Main.cc:37:35: warning: pointer to a function used in arithmetic [-Wpointer-arith] left[i] = (right[j] + left[i]) % MOD; ^ Main.cc:37:45: warning: pointer to a function used in arithmetic [-Wpointer-arith] left[i] = (right[j] + left[i]) % MOD; ^ Main.cc:37:37: error: invalid operands of types ‘std::ios_base&(std::ios_base&)’ and ‘std::ios_base&(std::ios_base&)’ to binary ‘operator+’ left[i] = (right[j] + left[i]) % MOD; ~~~~~~~~~^~~~~~~~~ Main.cc:44:28: warning: pointer to a function used in arithmetic [-Wpointer-arith] ans = (ans + left[i] + right[i]) % MOD; ^ Main.cc:44:20: warning: pointer to a function used in arithmetic [-Wpointer-arith] ans = (ans + left[i] + right[i]) % MOD; ~~~~^~~~~~~~~ Main.cc:44:39: warning: pointer to a function used in arithmetic [-Wpointer-arith] ans = (ans + left[i] + right[i]) % MOD; ^ Main.cc:44:30: error: invalid operands of types ‘std::ios_base& (*)(std::ios_base&)’ and ‘std::ios_base&(std::ios_base&)’ to binary ‘operator+’ ans = (ans + left[i] + right[i]) % MOD; ~~~~~~~~~~~~~~^~~~~~~~~~