Main.cc: In lambda function:
Main.cc:16:12: error: expected '{' before 'b'
s +=[i] b[i];
^
Main.cc: In function 'int main()':
Main.cc:16:5: error: no match for 'operator+=' (operand types are 'int' and 'main()::')
s +=[i] b[i];
^