View Compilation Error

0_0_13694542_1018.cpp: In function 'int main()':
0_0_13694542_1018.cpp:31:28: error: expected ';' before ')' token
    b[k++] = a[i] - a[i+3*p])*(a[i] - a[i+3*p])+(a[i+1] - a[i + 1 + 3*p])*(a[i+1] - a[i + 1 + 3*p])+(a[i+2] - a[i+2 + 3*p])*(a[i+2] - a[i+2+3*p]);
                            ^