View Compilation Error

0_0_38708215_29542.cpp: In function 'long long int gcd(long long int, long long int)':
0_0_38708215_29542.cpp:6:3: error: expected ';' before 'while'
    6 |  4     while (c = a%b) a = b, b = c;
      |   ^    ~~~~~
      |   ;
0_0_38708215_29542.cpp:7:3: error: expected ';' before 'return'
    7 |  5     return b;
      |   ^    ~~~~~~
      |   ;