View Compilation Error

0_0_29086531_21259.cpp: In function 'void input_build()':
0_0_29086531_21259.cpp:32:17: error: 'm' was not declared in this scope
     scanf("%d",&m);
                 ^
0_0_29086531_21259.cpp:39:47: error: 'add_edge' was not declared in this scope
         if(s[0]=='g') add_edge(st-1,st+len,k+1);
                                               ^
0_0_29086531_21259.cpp:40:55: error: 'add_edge' was not declared in this scope
         else if(s[0]=='l') add_edge(st+len,st-1,-(k-1));
                                                       ^
0_0_29086531_21259.cpp: In function 'int main()':
0_0_29086531_21259.cpp:71:22: error: invalid operands of types 'const char [3]' and 'int' to binary 'operator&'
     while(scanf("%d"&n)!=EOF&&n){
                      ^